diff --git a/src/main/java/ast/block/BlockNode.java b/src/main/java/ast/block/BlockNode.java
index a5ff3f7..67d9e81 100644
--- a/src/main/java/ast/block/BlockNode.java
+++ b/src/main/java/ast/block/BlockNode.java
@@ -2,11 +2,14 @@ package ast.block;
 
 import ast.ASTNode;
 import ast.statement.StatementNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
 
 import java.util.ArrayList;
 import java.util.List;
 
-public class BlockNode implements ASTNode {
+public class BlockNode implements ASTNode, Visitable {
     public List<StatementNode> statements = new ArrayList<>();
 
     public BlockNode() {}
@@ -14,4 +17,10 @@ public class BlockNode implements ASTNode {
     public void addStatement(StatementNode statement) {
         statements.add(statement);
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
+
 }
diff --git a/src/main/java/ast/expression/ExpressionNode.java b/src/main/java/ast/expression/ExpressionNode.java
index 1566f3b..282b9b7 100644
--- a/src/main/java/ast/expression/ExpressionNode.java
+++ b/src/main/java/ast/expression/ExpressionNode.java
@@ -1,4 +1,6 @@
 package ast.expression;
 
-public class ExpressionNode {
+import ast.ASTNode;
+
+public class ExpressionNode implements ASTNode {
 }
diff --git a/src/main/java/ast/expression/unaryexpression/UnaryExpressionNode.java b/src/main/java/ast/expression/unaryexpression/UnaryExpressionNode.java
index fdb694a..38c014d 100644
--- a/src/main/java/ast/expression/unaryexpression/UnaryExpressionNode.java
+++ b/src/main/java/ast/expression/unaryexpression/UnaryExpressionNode.java
@@ -7,7 +7,7 @@ import ast.type.ValueNode;
 
 import java.util.Objects;
 
-public class UnaryExpressionNode implements ASTNode {
+public class UnaryExpressionNode extends ExpressionNode {
     String thisExp;
     String identifier;
     MemberAccessNode memberAccess;
diff --git a/src/main/java/ast/member/MethodNode.java b/src/main/java/ast/member/MethodNode.java
index 2d79ee5..bedfac2 100644
--- a/src/main/java/ast/member/MethodNode.java
+++ b/src/main/java/ast/member/MethodNode.java
@@ -9,14 +9,15 @@ import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
 import visitor.Visitable;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class MethodNode implements MemberNode, Visitable {
     AccessModifierNode accesModifier;
-    TypeNode type;
+    public TypeNode type;
     Boolean voidType;
-    String identifier;
-    List<ParameterNode> parameters;
+    public String identifier;
+    private List<ParameterNode> parameters = new ArrayList<>();
     public BlockNode block;
 
     public MethodNode() {}
@@ -37,24 +38,23 @@ public class MethodNode implements MemberNode, Visitable {
         this.parameters.add(parameter);
     }
 
-    /*
-    public boolean isSame(MethodNode methodNode){
-        boolean isSame = false;
-        if(methodNode.identifier.equals(identifier)){
-            if(parameters != null && methodNode.parameters != null){
-                if(parameters.parameters.size() == methodNode.parameters.parameters.size()){
-                    for(int i = 0; i < parameters.parameters.size(); i++){
-                        if(parameters.parameters.get(i).identifier.equals(methodNode.parameters.parameters.get(i).identifier)){
-                            isSame = true;
-                        }
-                    }
-                }
-            }
-        }
-        return isSame;
+    public List<ParameterNode> getParameters() {
+        return parameters;
     }
 
-     */
+    public boolean isSame(MethodNode methodNode){
+        if (!this.identifier.equals(methodNode.identifier) || this.type.equals(methodNode.type)
+                || this.getParameters().size() != methodNode.getParameters().size()) {
+            return false;
+        }
+
+        for (int i = 0; i < this.getParameters().size(); i++) {
+            if (this.getParameters().get(i).type.equals(methodNode.getParameters().get(i).type)) {
+                return false;
+            }
+        }
+        return true;
+    }
 
     @Override
     public TypeCheckResult accept(SemanticVisitor visitor) {
diff --git a/src/main/java/ast/parameter/ParameterNode.java b/src/main/java/ast/parameter/ParameterNode.java
index 3a6b5ec..9050f30 100644
--- a/src/main/java/ast/parameter/ParameterNode.java
+++ b/src/main/java/ast/parameter/ParameterNode.java
@@ -2,13 +2,22 @@ package ast.parameter;
 
 import ast.ASTNode;
 import ast.type.TypeNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
 
-public class ParameterNode implements ASTNode {
-    TypeNode type;
-    String identifier;
+public class ParameterNode implements ASTNode, Visitable {
+    public TypeNode type;
+    public String identifier;
 
     public ParameterNode(TypeNode type, String identifier) {
         this.type = type;
         this.identifier = identifier;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
+
 }
diff --git a/src/main/java/ast/statement/LocalVariableDeclarationNode.java b/src/main/java/ast/statement/LocalVariableDeclarationNode.java
index 5b3900f..edee12b 100644
--- a/src/main/java/ast/statement/LocalVariableDeclarationNode.java
+++ b/src/main/java/ast/statement/LocalVariableDeclarationNode.java
@@ -4,7 +4,7 @@ import ast.ASTNode;
 import ast.expression.ExpressionNode;
 import ast.type.TypeNode;
 
-public class LocalVariableDeclarationNode implements ASTNode {
+public class LocalVariableDeclarationNode extends StatementNode {
     TypeNode type;
     String identifier;
     String assign;
diff --git a/src/main/java/ast/statement/StatementNode.java b/src/main/java/ast/statement/StatementNode.java
index c47d30c..e4e3862 100644
--- a/src/main/java/ast/statement/StatementNode.java
+++ b/src/main/java/ast/statement/StatementNode.java
@@ -1,2 +1,6 @@
-package ast.statement;public class StatementNode {
+package ast.statement;
+
+import ast.ASTNode;
+
+public class StatementNode implements ASTNode {
 }
diff --git a/src/main/java/ast/type/TypeNode.java b/src/main/java/ast/type/TypeNode.java
index 6336208..adb4892 100644
--- a/src/main/java/ast/type/TypeNode.java
+++ b/src/main/java/ast/type/TypeNode.java
@@ -22,4 +22,10 @@ public class TypeNode {
                 this.type = EnumTypeNode.IDENTIFIER;
         }
     }
+
+
+    public boolean equals(TypeNode o) {
+        return !o.type.equals(this.type);
+    }
+
 }
diff --git a/src/main/java/parser/astBuilder/ASTBuilder.java b/src/main/java/parser/astBuilder/ASTBuilder.java
index 7760b5c..fa59e98 100644
--- a/src/main/java/parser/astBuilder/ASTBuilder.java
+++ b/src/main/java/parser/astBuilder/ASTBuilder.java
@@ -74,7 +74,7 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
             } else {
                 MethodNode methodNode = new MethodNode((AccessModifierNode) visit(ctx.AccessModifier()), null, true, ctx.Identifier().getText(), (BlockNode) visit(ctx.block()));
                 for(SimpleJavaParser.ParameterContext parameter : ctx.parameterList().parameter()) {
-                    methodNode.addParameter((ParameterNode) visit(parameter));
+//                    methodNode.addParameter((ParameterNode) visit(parameter));
                 }
                 return methodNode;
             }
diff --git a/src/main/java/semantic/SemanticAnalyzer.java b/src/main/java/semantic/SemanticAnalyzer.java
index d3526f4..8c7e833 100644
--- a/src/main/java/semantic/SemanticAnalyzer.java
+++ b/src/main/java/semantic/SemanticAnalyzer.java
@@ -7,13 +7,14 @@ import java.util.List;
 import java.util.Objects;
 
 import ast.*;
+import ast.block.BlockNode;
 import ast.member.*;
+import ast.parameter.ParameterNode;
 import ast.statement.*;
 import ast.statement.ifstatement.IfStatementNode;
 import ast.type.*;
 import semantic.context.Context;
 import semantic.exeptions.AlreadyDeclearedException;
-import semantic.exeptions.NotDeclearedException;
 import semantic.exeptions.TypeMismatchException;
 import typechecker.TypeCheckResult;
 
@@ -96,10 +97,47 @@ public class SemanticAnalyzer implements SemanticVisitor {
     public TypeCheckResult analyze(MethodNode methodNode) {
         var valid = true;
 
-        currentScope.pushScope();
+        for (var otherMethod : currentClass.getMethods()) {
+            if (Objects.equals(otherMethod , methodNode))
+                break;
+            if (otherMethod.isSame(methodNode)) {
+                errors.add(new AlreadyDeclearedException(
+                        "Method " + methodNode.identifier + " is already defined in class "
+                                + currentClass.identifier));
+                valid = false;
+            }
+        }
 
+        currentScope.pushScope();
+        for (var parameter : methodNode.getParameters()) {
+            var result = parameter.accept(this);
+            valid = valid && result.isValid();
+            currentScope.addLocalVar(parameter.identifier, parameter.type);
+        }
+        // Check if this method is already declared
+
+//        currentMethodReturnType = methodDecl.getType();
+//        currentNullType = currentMethodReturnType; // Solange nicht in einem Assign oder Methoden-Aufruf dieser Typ
+
+        // gesetzt ist, ist dieser der Rückgabewert der Methode
+        var result = methodNode.block.accept(this);
+        valid = valid && result.isValid();
         currentScope.popScope();
-        return new TypeCheckResult(valid, null);
+        var resultType = result.getType();
+
+        /*
+        if (resultType == null) {
+            resultType = new BaseType(Primitives.VOID);
+        }
+        if (!resultType.equals(methodDecl.getType())) {
+            errors.add(new TypeMismatchException("Method-Declaration " + methodDecl.getIdentifier() + " with type "
+                    + methodDecl.getType() + " has at least one Mismatching return Type:"
+                    + TypeHelper.generateLocationString(methodDecl.line, methodDecl.column, fileName)));
+            valid = false;
+        }
+
+        */
+        return new TypeCheckResult(valid, resultType);
     }
 
     @Override
@@ -128,4 +166,14 @@ public class SemanticAnalyzer implements SemanticVisitor {
         return null;
     }
 
+    @Override
+    public TypeCheckResult analyze(ParameterNode toCheck) {
+        return new TypeCheckResult(true, null);
+    }
+
+    @Override
+    public TypeCheckResult analyze(BlockNode toCheck) {
+        return new TypeCheckResult(true, null);
+    }
+
 }
\ No newline at end of file
diff --git a/src/main/java/semantic/SemanticVisitor.java b/src/main/java/semantic/SemanticVisitor.java
index 6bdc9a8..aca196b 100644
--- a/src/main/java/semantic/SemanticVisitor.java
+++ b/src/main/java/semantic/SemanticVisitor.java
@@ -2,7 +2,9 @@ package semantic;
 
 
 import ast.*;
+import ast.block.BlockNode;
 import ast.member.*;
+import ast.parameter.ParameterNode;
 import ast.statement.*;
 import ast.statement.ifstatement.*;
 import typechecker.TypeCheckResult;
@@ -23,4 +25,9 @@ public interface SemanticVisitor {
 
     TypeCheckResult analyze(WhileStatementNode toCheck);
 
+    TypeCheckResult analyze(ParameterNode toCheck);
+
+    TypeCheckResult analyze(BlockNode toCheck);
+
+
 }
\ No newline at end of file
diff --git a/src/test/java/semantic/Mocker.java b/src/test/java/semantic/Mocker.java
index a60e83b..5a5e014 100644
--- a/src/test/java/semantic/Mocker.java
+++ b/src/test/java/semantic/Mocker.java
@@ -2,7 +2,13 @@ package semantic;
 
 import ast.*;
 import ast.block.BlockNode;
+import ast.member.FieldNode;
 import ast.member.MethodNode;
+import ast.parameter.ParameterNode;
+import ast.statement.StatementNode;
+import ast.statement.statementexpression.NewDeclarationStatementExpressionNode;
+import ast.type.AccessModifierNode;
+import ast.type.TypeNode;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -11,26 +17,94 @@ import static parser.generated.SimpleJavaParser.Identifier;
 
 public class Mocker {
 
-    public static ProgramNode mockCorrectClass(){
+    public static ASTNode mockTwoSameFields(){
         ProgramNode p = new ProgramNode();
 
         ClassNode c = new ClassNode();
         c.identifier = "testClass";
 
-        MethodNode m = new MethodNode();
+        FieldNode f1 = new FieldNode(new AccessModifierNode("public"), new TypeNode("int"), "a");
 
-        BlockNode b = new BlockNode();
+        c.members.add(f1);
 
+        FieldNode f2 = new FieldNode(new AccessModifierNode("public"), new TypeNode("int"), "a");
 
-
-//        b.statements.add();
-
-        m.block = b;
-
-        c.members.add(m);
+        c.members.add(f2);
 
         p.classes.add(c);
         return p;
     }
 
+    public static ASTNode mockSimpleMethod(){
+        ProgramNode p = new ProgramNode();
+
+        ClassNode c = new ClassNode();
+
+        MethodNode methodNode = new MethodNode();
+
+        //Parameter
+        ParameterNode parameterNode = new ParameterNode(new TypeNode("int"), "a");
+
+        methodNode.addParameter(parameterNode);
+
+        //Statements
+
+        //Block
+        methodNode.block = new BlockNode();
+
+        c.members.add(methodNode);
+
+        p.classes.add(c);
+
+        return p;
+    }
+
+    public static ASTNode mockTwoSameMethods(){
+        ProgramNode p = new ProgramNode();
+
+        ClassNode c = new ClassNode();
+
+        MethodNode methodNode = new MethodNode();
+        methodNode.block = new BlockNode();
+        methodNode.type = new TypeNode("int");
+
+        methodNode.identifier = "testMethod";
+
+        c.members.add(methodNode);
+
+        MethodNode methodNode1 = new MethodNode();
+        methodNode1.block = new BlockNode();
+        methodNode1.type = new TypeNode("int");
+
+        methodNode1.identifier = "testMethod";
+
+        c.members.add(methodNode1);
+
+        p.classes.add(c);
+
+        return p;
+    }
+
+    public static ASTNode mockTwoDifferentMethods(){
+        ProgramNode p = new ProgramNode();
+
+        ClassNode c = new ClassNode();
+
+        MethodNode methodNode = new MethodNode();
+        methodNode.block = new BlockNode();
+        methodNode.identifier = "testMethod";
+
+        c.members.add(methodNode);
+
+        MethodNode methodNode1 = new MethodNode();
+        methodNode1.block = new BlockNode();
+        methodNode1.identifier = "testMethod1";
+
+        c.members.add(methodNode1);
+
+        p.classes.add(c);
+
+        return p;
+    }
+
 }
diff --git a/src/test/java/semantic/SemanticTest.java b/src/test/java/semantic/SemanticTest.java
index 8554022..7ebc7ad 100644
--- a/src/test/java/semantic/SemanticTest.java
+++ b/src/test/java/semantic/SemanticTest.java
@@ -1,14 +1,63 @@
 package semantic;
 
+import ast.ASTNode;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import semantic.exeptions.AlreadyDeclearedException;
+
+import static org.junit.jupiter.api.Assertions.*;
 
 public class SemanticTest {
 
+    @BeforeEach
+    public void setup(){
+        SemanticAnalyzer.clearAnalyzier();
+    }
+
     @Test
-    public void correctClass(){
+    public void twoFieldsSameName() {
 
+        ASTNode ast = Mocker.mockTwoSameFields();
 
+        ASTNode tast = SemanticAnalyzer.generateTast(ast);
+
+        assertEquals(SemanticAnalyzer.errors.size(), 1);
+        assertInstanceOf(AlreadyDeclearedException.class, SemanticAnalyzer.errors.getFirst());
+        assertNull(tast);
 
     }
 
+    @Test
+    public void simpleMethod(){
+
+        ASTNode ast = Mocker.mockSimpleMethod();
+
+        ASTNode tast = SemanticAnalyzer.generateTast(ast);
+
+        assertEquals(SemanticAnalyzer.errors.size(), 0);
+        assertNotNull(tast);
+
+    }
+
+    @Test
+    public void twoSameMethods(){
+        ASTNode ast = Mocker.mockTwoSameMethods();
+
+        ASTNode tast = SemanticAnalyzer.generateTast(ast);
+
+        assertEquals(1, SemanticAnalyzer.errors.size());
+        assertInstanceOf(AlreadyDeclearedException.class, SemanticAnalyzer.errors.getFirst());
+        assertNull(tast);
+    }
+
+    @Test
+    public void twoDifferentMethods(){
+        ASTNode ast = Mocker.mockTwoDifferentMethods();
+
+        ASTNode tast = SemanticAnalyzer.generateTast(ast);
+
+        assertEquals(SemanticAnalyzer.errors.size(), 0);
+        assertNotNull(tast);
+    }
+
 }
diff --git a/src/test/java/semantic/endToTAST/CorrectTest.java b/src/test/java/semantic/endToTAST/CorrectTest.java
index a8280fe..e3a7a08 100644
--- a/src/test/java/semantic/endToTAST/CorrectTest.java
+++ b/src/test/java/semantic/endToTAST/CorrectTest.java
@@ -1,5 +1,6 @@
 package semantic.endToTAST;
 
+import ast.ASTNode;
 import ast.ProgramNode;
 import org.antlr.v4.runtime.CharStream;
 import org.antlr.v4.runtime.CharStreams;
@@ -9,10 +10,13 @@ import org.junit.jupiter.api.Test;
 import parser.astBuilder.ASTBuilder;
 import parser.generated.SimpleJavaLexer;
 import parser.generated.SimpleJavaParser;
+import semantic.SemanticAnalyzer;
 
 import java.io.IOException;
 import java.nio.file.Paths;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 public class CorrectTest {
 
     @Test
@@ -36,6 +40,12 @@ public class CorrectTest {
 
         System.out.println("Test");
 
+        ASTNode tast = SemanticAnalyzer.generateTast(abstractSyntaxTree);
+
+        System.out.println("Errors: " + SemanticAnalyzer.errors.size());
+
+        assertEquals(SemanticAnalyzer.errors.size(), 0);
+
     }
 
 }
diff --git a/src/test/resources/semantic/endToTAST/Test.java b/src/test/resources/semantic/endToTAST/Test.java
index bd4e673..d067998 100644
--- a/src/test/resources/semantic/endToTAST/Test.java
+++ b/src/test/resources/semantic/endToTAST/Test.java
@@ -1,7 +1,6 @@
 public class Test {
 
-    public void test(){
-
-    }
+    public boolean b;
+    public boolean b;
 
 }
\ No newline at end of file