diff --git a/src/main/java/ast/AssignmentNode.java b/src/main/java/ast/AssignmentNode.java
deleted file mode 100644
index 38e7fb9..0000000
--- a/src/main/java/ast/AssignmentNode.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package ast;
-
-public class AssignmentNode extends StatementNode {
-
-  public Identifier identifier;
-
-  public ExpressionNode expression;
-
-  public AssignmentNode(String identifier, ExpressionNode expression) {
-    this.identifier = new Identifier(identifier);
-    this.expression = expression;
-  }
-
-}
diff --git a/src/main/java/ast/BlockNode.java b/src/main/java/ast/BlockNode.java
new file mode 100644
index 0000000..2dd5307
--- /dev/null
+++ b/src/main/java/ast/BlockNode.java
@@ -0,0 +1,4 @@
+package ast;
+
+public class BlockNode {
+}
diff --git a/src/main/java/ast/ClassNode.java b/src/main/java/ast/ClassNode.java
index dd390ee..81dc844 100644
--- a/src/main/java/ast/ClassNode.java
+++ b/src/main/java/ast/ClassNode.java
@@ -1,10 +1,13 @@
 package ast;
 
+import ast.type.AccessTypeNode;
+import ast.type.EnumAccessTypeNode;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public class ClassNode extends ASTNode{
-    public Identifier identifier;
+    public IdentifierNode identifier;
     public AccessTypeNode accessType;
     public String name;
     public List<MemberNode> members = new ArrayList<>();
diff --git a/src/main/java/ast/ConstructorNode.java b/src/main/java/ast/ConstructorNode.java
index a824f5a..94108b8 100644
--- a/src/main/java/ast/ConstructorNode.java
+++ b/src/main/java/ast/ConstructorNode.java
@@ -1,5 +1,7 @@
 package ast;
 
+import ast.type.AccessTypeNode;
+
 public class ConstructorNode extends MethodNode{
     public ConstructorNode(AccessTypeNode visibility, String name) {
         super(visibility, name);
diff --git a/src/main/java/ast/ExpressionNode.java b/src/main/java/ast/ExpressionNode.java
deleted file mode 100644
index 9e6f2a8..0000000
--- a/src/main/java/ast/ExpressionNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package ast;
-
-public class ExpressionNode extends ASTNode {
-
-  int Value;
-
-  public ExpressionNode(int value) {
-    this.Value = value;
-  }
-
-}
diff --git a/src/main/java/ast/FieldNode.java b/src/main/java/ast/FieldNode.java
index 3d0d287..4e316c1 100644
--- a/src/main/java/ast/FieldNode.java
+++ b/src/main/java/ast/FieldNode.java
@@ -1,14 +1,16 @@
 package ast;
 
+import ast.type.AccessTypeNode;
+
 public class FieldNode extends MemberNode {
     public AccessTypeNode accessTypeNode;
     public TypeNode type;
-    public Identifier identifier;
+    public IdentifierNode identifier;
 
     public FieldNode(AccessTypeNode accessTypeNode, TypeNode type, String name){
         this.accessTypeNode = accessTypeNode;
         this.type = type;
-        this.identifier = new Identifier(name);
+        this.identifier = new IdentifierNode(name);
     }
 
 }
diff --git a/src/main/java/ast/Identifier.java b/src/main/java/ast/IdentifierNode.java
similarity index 67%
rename from src/main/java/ast/Identifier.java
rename to src/main/java/ast/IdentifierNode.java
index 2f6fe73..3300633 100644
--- a/src/main/java/ast/Identifier.java
+++ b/src/main/java/ast/IdentifierNode.java
@@ -1,10 +1,10 @@
 package ast;
 
-public class Identifier {
+public class IdentifierNode {
 
     private String name;
 
-    public Identifier(String name){
+    public IdentifierNode(String name){
         this.name = name;
     }
 
@@ -13,8 +13,8 @@ public class Identifier {
     }
 
     public boolean equals(Object obj) {
-        if(obj instanceof Identifier){
-            Identifier identifier = (Identifier) obj;
+        if(obj instanceof IdentifierNode){
+            IdentifierNode identifier = (IdentifierNode) obj;
             if(name.equals(identifier.getName())){
                 return true;
             } else {
diff --git a/src/main/java/ast/MethodNode.java b/src/main/java/ast/MethodNode.java
index d9058c5..2c4e1e9 100644
--- a/src/main/java/ast/MethodNode.java
+++ b/src/main/java/ast/MethodNode.java
@@ -1,10 +1,13 @@
 package ast;
 
+import ast.statement.StatementNode;
+import ast.type.AccessTypeNode;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public class MethodNode extends MemberNode{
-    public Identifier identifier;
+    public IdentifierNode identifier;
     public AccessTypeNode visibility;
     public TypeNode type;
     public String name;
@@ -16,7 +19,7 @@ public class MethodNode extends MemberNode{
     public MethodNode(AccessTypeNode visibility, TypeNode type, String name, ParameterListNode parameters,
                       List<StatementNode> statements){
         this.visibility = visibility;
-        this.identifier = new Identifier(name);
+        this.identifier = new IdentifierNode(name);
         this.type = type;
         this.name = name;
         this.parameters = parameters;
@@ -25,6 +28,6 @@ public class MethodNode extends MemberNode{
 
     public MethodNode(AccessTypeNode visibility, String name){
         this.visibility = visibility;
-        this.identifier = new Identifier(name);
+        this.identifier = new IdentifierNode(name);
     }
 }
diff --git a/src/main/java/ast/TypeNode.java b/src/main/java/ast/TypeNode.java
index fd921b6..4733bc8 100644
--- a/src/main/java/ast/TypeNode.java
+++ b/src/main/java/ast/TypeNode.java
@@ -1,5 +1,7 @@
 package ast;
 
+import ast.type.EnumTypeNode;
+
 public class TypeNode extends ASTNode {
     public EnumTypeNode enumTypeNode;
 
diff --git a/src/main/java/ast/expression/BinaryExpressionNode.java b/src/main/java/ast/expression/BinaryExpressionNode.java
new file mode 100644
index 0000000..e63bbca
--- /dev/null
+++ b/src/main/java/ast/expression/BinaryExpressionNode.java
@@ -0,0 +1,13 @@
+package ast.expression;
+
+public class BinaryExpressionNode extends ExpressionNode {
+    public ExpressionNode left;
+    public ExpressionNode right;
+    public String operator;  // Stores the operator as a string (e.g., "+", "-", "&&")
+
+    public BinaryExpressionNode(ExpressionNode left, ExpressionNode right, String operator) {
+        this.left = left;
+        this.right = right;
+        this.operator = operator;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ast/expression/ExpressionNode.java b/src/main/java/ast/expression/ExpressionNode.java
new file mode 100644
index 0000000..eff9d29
--- /dev/null
+++ b/src/main/java/ast/expression/ExpressionNode.java
@@ -0,0 +1,7 @@
+package ast.expression;
+
+import ast.ASTNode;
+
+public class ExpressionNode extends ASTNode {
+
+}
diff --git a/src/main/java/ast/expression/IdentifierExpressionNode.java b/src/main/java/ast/expression/IdentifierExpressionNode.java
new file mode 100644
index 0000000..7631429
--- /dev/null
+++ b/src/main/java/ast/expression/IdentifierExpressionNode.java
@@ -0,0 +1,9 @@
+package ast.expression;
+
+public class IdentifierExpressionNode extends ExpressionNode {
+    public String name;
+
+    public IdentifierExpressionNode(String name) {
+        this.name = name;
+    }
+}
diff --git a/src/main/java/ast/expression/UnaryExpressionNode.java b/src/main/java/ast/expression/UnaryExpressionNode.java
new file mode 100644
index 0000000..0c77ef5
--- /dev/null
+++ b/src/main/java/ast/expression/UnaryExpressionNode.java
@@ -0,0 +1,11 @@
+package ast.expression;
+
+public class UnaryExpressionNode extends ExpressionNode {
+    public ExpressionNode expression;
+    public String operator;  // Stores the operator (e.g., "-", "!")
+
+    public UnaryExpressionNode(ExpressionNode expression, String operator) {
+        this.expression = expression;
+        this.operator = operator;
+    }
+}
diff --git a/src/main/java/ast/statement/AssignmentStatementNode.java b/src/main/java/ast/statement/AssignmentStatementNode.java
new file mode 100644
index 0000000..97bcd45
--- /dev/null
+++ b/src/main/java/ast/statement/AssignmentStatementNode.java
@@ -0,0 +1,13 @@
+package ast.statement;
+
+import ast.expression.ExpressionNode;
+
+public class AssignmentStatementNode extends StatementNode {
+  public String identifier;
+  public ExpressionNode expression;
+
+  public AssignmentStatementNode(String identifier, ExpressionNode expression) {
+    this.identifier = identifier;
+    this.expression = expression;
+  }
+}
diff --git a/src/main/java/ast/statement/IfStatementNode.java b/src/main/java/ast/statement/IfStatementNode.java
new file mode 100644
index 0000000..93eec91
--- /dev/null
+++ b/src/main/java/ast/statement/IfStatementNode.java
@@ -0,0 +1,15 @@
+package ast.statement;
+
+import ast.expression.ExpressionNode;
+
+public class IfStatementNode extends StatementNode {
+    public ExpressionNode condition;
+    public StatementNode thenStatement;
+    public StatementNode elseStatement;
+
+    public IfStatementNode(ExpressionNode condition, StatementNode thenStatement, StatementNode elseStatement) {
+        this.condition = condition;
+        this.thenStatement = thenStatement;
+        this.elseStatement = elseStatement;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ast/statement/ReturnStatementNode.java b/src/main/java/ast/statement/ReturnStatementNode.java
new file mode 100644
index 0000000..4ca4dfa
--- /dev/null
+++ b/src/main/java/ast/statement/ReturnStatementNode.java
@@ -0,0 +1,11 @@
+package ast.statement;
+
+import ast.expression.ExpressionNode;
+
+public class ReturnStatementNode extends StatementNode {
+    public ExpressionNode expression;
+
+    public ReturnStatementNode(ExpressionNode expression) {
+        this.expression = expression;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ast/StatementNode.java b/src/main/java/ast/statement/StatementNode.java
similarity index 77%
rename from src/main/java/ast/StatementNode.java
rename to src/main/java/ast/statement/StatementNode.java
index 059a96a..910a134 100644
--- a/src/main/java/ast/StatementNode.java
+++ b/src/main/java/ast/statement/StatementNode.java
@@ -1,4 +1,4 @@
-package ast;
+package ast.statement;
 
 import ast.ASTNode;
 
diff --git a/src/main/java/ast/VariableDeclarationStatementNode.java b/src/main/java/ast/statement/VariableDeclarationStatementNode.java
similarity index 73%
rename from src/main/java/ast/VariableDeclarationStatementNode.java
rename to src/main/java/ast/statement/VariableDeclarationStatementNode.java
index 6222942..1095fd6 100644
--- a/src/main/java/ast/VariableDeclarationStatementNode.java
+++ b/src/main/java/ast/statement/VariableDeclarationStatementNode.java
@@ -1,10 +1,12 @@
-package ast;
+package ast.statement;
+
+import ast.TypeNode;
+import ast.expression.ExpressionNode;
 
 public class VariableDeclarationStatementNode extends StatementNode {
     public TypeNode type;
     public String identifier;
-    public ExpressionNode expression; // Nullable for cases without initialization
-
+    public ExpressionNode expression;
     public VariableDeclarationStatementNode(TypeNode type, String identifier, ExpressionNode expression) {
         this.type = type;
         this.identifier = identifier;
diff --git a/src/main/java/ast/statement/WhileStatementNode.java b/src/main/java/ast/statement/WhileStatementNode.java
new file mode 100644
index 0000000..e6a10b1
--- /dev/null
+++ b/src/main/java/ast/statement/WhileStatementNode.java
@@ -0,0 +1,13 @@
+package ast.statement;
+
+import ast.expression.ExpressionNode;
+
+public class WhileStatementNode extends StatementNode {
+    public ExpressionNode condition;
+    public StatementNode body;
+
+    public WhileStatementNode(ExpressionNode condition, StatementNode body) {
+        this.condition = condition;
+        this.body = body;
+    }
+}
diff --git a/src/main/java/ast/AccessTypeNode.java b/src/main/java/ast/type/AccessTypeNode.java
similarity index 85%
rename from src/main/java/ast/AccessTypeNode.java
rename to src/main/java/ast/type/AccessTypeNode.java
index 2ed2e55..ddacf68 100644
--- a/src/main/java/ast/AccessTypeNode.java
+++ b/src/main/java/ast/type/AccessTypeNode.java
@@ -1,4 +1,6 @@
-package ast;
+package ast.type;
+
+import ast.ASTNode;
 
 public class AccessTypeNode extends ASTNode {
     public EnumAccessTypeNode enumAccessTypeNode;
diff --git a/src/main/java/ast/EnumAccessTypeNode.java b/src/main/java/ast/type/EnumAccessTypeNode.java
similarity index 75%
rename from src/main/java/ast/EnumAccessTypeNode.java
rename to src/main/java/ast/type/EnumAccessTypeNode.java
index 2e6ffba..12cdda9 100644
--- a/src/main/java/ast/EnumAccessTypeNode.java
+++ b/src/main/java/ast/type/EnumAccessTypeNode.java
@@ -1,4 +1,4 @@
-package ast;
+package ast.type;
 
 public enum EnumAccessTypeNode {
     PUBLIC, PRIVATE
diff --git a/src/main/java/ast/EnumTypeNode.java b/src/main/java/ast/type/EnumTypeNode.java
similarity index 74%
rename from src/main/java/ast/EnumTypeNode.java
rename to src/main/java/ast/type/EnumTypeNode.java
index b80cd57..d858461 100644
--- a/src/main/java/ast/EnumTypeNode.java
+++ b/src/main/java/ast/type/EnumTypeNode.java
@@ -1,4 +1,4 @@
-package ast;
+package ast.type;
 
 public enum EnumTypeNode {
     INT, BOOLEAN, CHAR
diff --git a/src/main/java/bytecode/Mapper.java b/src/main/java/bytecode/Mapper.java
index 872f8e1..168e1e2 100644
--- a/src/main/java/bytecode/Mapper.java
+++ b/src/main/java/bytecode/Mapper.java
@@ -1,7 +1,7 @@
 package bytecode;
 
-import ast.AccessTypeNode;
-import ast.EnumAccessTypeNode;
+import ast.type.AccessTypeNode;
+import ast.type.EnumAccessTypeNode;
 import org.objectweb.asm.Opcodes;
 
 public class Mapper {
diff --git a/src/main/java/parser/ASTBuilder.java b/src/main/java/parser/ASTBuilder.java
index e90ba95..c4f9374 100644
--- a/src/main/java/parser/ASTBuilder.java
+++ b/src/main/java/parser/ASTBuilder.java
@@ -1,12 +1,20 @@
 package parser;
 
 import ast.*;
+import ast.expression.BinaryExpressionNode;
+import ast.expression.ExpressionNode;
+import ast.expression.IdentifierExpressionNode;
+import ast.expression.UnaryExpressionNode;
+import ast.statement.*;
+import ast.type.AccessTypeNode;
+import ast.type.EnumAccessTypeNode;
+import ast.type.EnumTypeNode;
+import org.antlr.v4.runtime.tree.TerminalNode;
 import parser.generated.SimpleJavaBaseVisitor;
 import parser.generated.SimpleJavaParser;
 
 import java.util.ArrayList;
 import java.util.List;
-import parser.generated.SimpleJavaParser.LiteralContext;
 
 public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
     @Override
@@ -21,7 +29,7 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
     @Override
     public ASTNode visitClassDeclaration(SimpleJavaParser.ClassDeclarationContext ctx) {
         ClassNode classNode = new ClassNode((AccessTypeNode) visit(ctx.accessType()),ctx.IDENTIFIER().getText());
-        classNode.identifier = new Identifier(ctx.IDENTIFIER().getText());
+        classNode.identifier = new IdentifierNode(ctx.IDENTIFIER().getText());
         for (SimpleJavaParser.MemberDeclarationContext member : ctx.memberDeclaration()) {
             classNode.addMember((MemberNode) visit(member));
         }
@@ -108,26 +116,78 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
         return null;
     }
 
+    @Override
+    public ASTNode visitVariableDeclarationStatement(SimpleJavaParser.VariableDeclarationStatementContext ctx) {
+        TypeNode type = (TypeNode) visit(ctx.type());
+        String identifier = ctx.IDENTIFIER().getText();
+        ExpressionNode expression = null;
+        if (ctx.expression() != null) {
+            expression = (ExpressionNode) visit(ctx.expression());
+        }
+        return new VariableDeclarationStatementNode(type, identifier, expression);
+    }
+
     @Override
     public ASTNode visitAssignmentStatement(SimpleJavaParser.AssignmentStatementContext ctx) {
-        ExpressionNode expressionNode = (ExpressionNode) visit(ctx.expression());
-        return new AssignmentNode(ctx.IDENTIFIER().getText(), expressionNode);
+        String identifier = ctx.IDENTIFIER().getText();
+        ExpressionNode expression = (ExpressionNode) visit(ctx.expression());
+        return new AssignmentStatementNode(identifier, expression);
+    }
+
+    @Override
+    public ASTNode visitIfStatement(SimpleJavaParser.IfStatementContext ctx) {
+        ExpressionNode condition = (ExpressionNode) visit(ctx.expression());
+        StatementNode thenStatement = (StatementNode) visit(ctx.statement(0)); // The 'then' branch
+        StatementNode elseStatement = null;
+        if (ctx.statement().size() > 1) {
+            elseStatement = (StatementNode) visit(ctx.statement(1)); // The 'else' branch, if present
+        }
+        return new IfStatementNode(condition, thenStatement, elseStatement);
+    }
+
+    @Override
+    public ASTNode visitWhileStatement(SimpleJavaParser.WhileStatementContext ctx) {
+        ExpressionNode condition = (ExpressionNode) visit(ctx.expression());  // Visit the condition part of the while statement
+        StatementNode body = (StatementNode) visit(ctx.statement());  // Visit the body part of the while statement
+        return new WhileStatementNode(condition, body);
+    }
+
+    @Override
+    public ASTNode visitReturnStatement(SimpleJavaParser.ReturnStatementContext ctx) {
+        ExpressionNode expression = null;
+        if (ctx.expression() != null) {
+            expression = (ExpressionNode) visit(ctx.expression());  // Visit the expression part of the return statement, if it exists
+        }
+        return new ReturnStatementNode(expression);
     }
 
     @Override
     public ASTNode visitExpression(SimpleJavaParser.ExpressionContext ctx) {
-        if(ctx.literal() != null){
-            return visitLiteral(ctx.literal());
+        // Handle binary operations
+        if (ctx.getChildCount() == 3 && ctx.getChild(1) instanceof TerminalNode) {
+            ExpressionNode left = (ExpressionNode) visit(ctx.expression(0));
+            ExpressionNode right = (ExpressionNode) visit(ctx.expression(1));
+            String operator = ctx.getChild(1).getText();
+            return new BinaryExpressionNode(left, right, operator);
         }
-        return null;
-    }
-
-    @Override
-    public ASTNode visitLiteral(SimpleJavaParser.LiteralContext ctx) {
-        if(ctx.INTEGERLITERAL() != null){
-            return new ExpressionNode(Integer.parseInt(ctx.INTEGERLITERAL().getSymbol().getText()));
+        // Handle unary operations
+        else if (ctx.getChildCount() == 2) {
+            String operator = ctx.getChild(0).getText();
+            ExpressionNode expression = (ExpressionNode) visit(ctx.expression(0));
+            return new UnaryExpressionNode(expression, operator);
+        }
+        // Handle parentheses
+        else if (ctx.getChildCount() == 3 && ctx.getChild(0).getText().equals("(")) {
+            return visit(ctx.expression(0));  // Simply return the inner expression
+        }
+        // Handle literals and identifiers
+        else if (ctx.literal() != null) {
+            return visit(ctx.literal());
+        }
+        else if (ctx.IDENTIFIER() != null) {
+            return new IdentifierExpressionNode(ctx.IDENTIFIER().getText());
         }
-        return null;
-    }
 
+        return null;  // Return null or throw an exception if no valid expression found
+    }
 }
diff --git a/src/main/java/semantic/SemanticAnalyzer.java b/src/main/java/semantic/SemanticAnalyzer.java
index 315a51e..940a0dc 100644
--- a/src/main/java/semantic/SemanticAnalyzer.java
+++ b/src/main/java/semantic/SemanticAnalyzer.java
@@ -8,7 +8,7 @@ import java.util.List;
 
 public class SemanticAnalyzer {
 
-    List<Identifier> usedIdentifier = new ArrayList<>();
+    List<IdentifierNode> usedIdentifier = new ArrayList<>();
 
     public void analyze(ASTNode node) {
         if (node == null) return;
@@ -47,7 +47,7 @@ public class SemanticAnalyzer {
 
     }
 
-    public boolean identifierAlreadyUsed(Identifier identifier){
+    public boolean identifierAlreadyUsed(IdentifierNode identifier){
         if(usedIdentifier.contains(identifier)){
             return true;
         } else {