diff --git a/Source/Compiler.java b/Source/Compiler.java
index d993d97..871cc22 100644
--- a/Source/Compiler.java
+++ b/Source/Compiler.java
@@ -25,7 +25,7 @@ public class Compiler {
 //        String content = new String(Files.readAllBytes(Paths.get(filePath)));
 //        CharArrayReader charStream = new CharArrayReader(content.toCharArray());
 
-        CharStream codeCharStream = CharStreams.fromString("class Example { }");
+        CharStream codeCharStream = CharStreams.fromString("class Example { int i; }");
         DecafLexer lexer = new DecafLexer(codeCharStream);
         CommonTokenStream tokens = new CommonTokenStream(lexer);
 
@@ -36,7 +36,7 @@ public class Compiler {
 
         StringBuilder stringBuilder = new StringBuilder();
         for (Token token : tokenList) {
-            stringBuilder.append(token.toString()).append(" ");
+            stringBuilder.append(token.getText()).append(" ");
         }
         String readableTokens = stringBuilder.toString().trim();
 
@@ -53,9 +53,6 @@ public class Compiler {
 
 
         Program abstractSyntaxTree = new Program(new ArrayList<>());
-        List<FieldDecl> emptyFieldDecl = new ArrayList<>();
-        List<MethodDecl> emptyMethodDecl = new ArrayList<>();
-        abstractSyntaxTree.classes.add(new RefType(emptyFieldDecl, emptyMethodDecl, null, null, "MyClass"));
 
         abstractSyntaxTree.typeCheck();
 
diff --git a/Source/EmptyClass.java b/Source/EmptyClass.java
index a3496cf..2a388fa 100644
--- a/Source/EmptyClass.java
+++ b/Source/EmptyClass.java
@@ -1,2 +1,3 @@
 class EmptyClass {
+
 }
diff --git a/Source/TypeCheck/TypeCheckHelper.java b/Source/TypeCheck/TypeCheckHelper.java
index bd4aa58..5d487d8 100644
--- a/Source/TypeCheck/TypeCheckHelper.java
+++ b/Source/TypeCheck/TypeCheckHelper.java
@@ -21,12 +21,12 @@ public class TypeCheckHelper {
         }
         return result;
     }
-    public static boolean typeExists(String type, List<String> typeslist) {
+    public static boolean typeExists(String type, List<String> customTypeslist) {
 
         if(type.equals("int") || type.equals("bool") || type.equals("char")){
             return true;
         }
-        return typeslist.contains(type);
+        return customTypeslist.contains(type);
     }
 
 }
diff --git a/Source/abstractSyntaxTree/Class/FieldDecl.java b/Source/abstractSyntaxTree/Class/FieldDecl.java
index a02fb36..355a9fb 100644
--- a/Source/abstractSyntaxTree/Class/FieldDecl.java
+++ b/Source/abstractSyntaxTree/Class/FieldDecl.java
@@ -12,21 +12,19 @@ import java.util.List;
 
 public class FieldDecl extends AbstractType implements IClass{
 
-    private HashMap<String, HashMap<String, String>> typeContext; // form class from program
     public  String type; // from parser
     public String identifier; // from parser
 
-    public FieldDecl(HashMap<String, HashMap<String, String>> typeContext){
-        this.typeContext = typeContext;
+    public FieldDecl(String type, String identifier){
+        this.type = type;
+        this.identifier = identifier;
     }
-    public TypeCheckResult typeCheck(List<FieldDecl> classFieldsIdentifier) throws Exception {
+    public TypeCheckResult typeCheck(HashMap<String, HashMap<String, String>> typeContext) throws Exception {
+
         TypeCheckResult result = new TypeCheckResult();
-        if (classFieldsIdentifier.contains(this.identifier)){
-            throw new Exception("field already defined");
-        } else {
-            classFieldsIdentifier.add(this);
-        }
-        //TypeCheckHelper.typeExists(type, ) // need all types of classes
+
+        TypeCheckHelper.typeExists(this.type, typeContext.keySet().stream().toList());
+        result.type = this.type;
         setTypeCheckResult(result);
 
         return result;
@@ -34,7 +32,6 @@ public class FieldDecl extends AbstractType implements IClass{
         //write field table
     }
 
-    @Override
     public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext, HashMap<String, HashMap<String, String>> typeContext, List<MethodDecl> fieldsOrMethods) throws Exception {
         return null;
     }
diff --git a/Source/abstractSyntaxTree/Class/IClass.java b/Source/abstractSyntaxTree/Class/IClass.java
index cfd14e3..dae625a 100644
--- a/Source/abstractSyntaxTree/Class/IClass.java
+++ b/Source/abstractSyntaxTree/Class/IClass.java
@@ -10,7 +10,6 @@ import java.util.List;
 public interface IClass {
     // visit method for code generation
 
-    TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext, HashMap<String, HashMap<String, String>> typeContext, List<MethodDecl> fieldsOrMethods) throws Exception;
     void codeGen(ClassWriter cw) throws Exception;
 
 }
diff --git a/Source/abstractSyntaxTree/Class/MethodDecl.java b/Source/abstractSyntaxTree/Class/MethodDecl.java
index 6e12a51..ef7181f 100644
--- a/Source/abstractSyntaxTree/Class/MethodDecl.java
+++ b/Source/abstractSyntaxTree/Class/MethodDecl.java
@@ -2,6 +2,7 @@ package abstractSyntaxTree.Class;
 
 import TypeCheck.TypeCheckResult;
 import abstractSyntaxTree.Program;
+import abstractSyntaxTree.Statement.IStatement;
 import org.objectweb.asm.ClassWriter;
 
 import java.util.HashMap;
@@ -13,15 +14,20 @@ public class MethodDecl implements IClass {
     public String name;
     public List<String> parameters;
     public String returnType;
+    public List<IStatement> codeBlock;
 
+    // save localvars
 
-    //TODO: Move this into the typeCheck
-    private HashMap<String, String> localVars; // (type, identifier) // add content here
+    public MethodDecl(String classThatContainsMethod, String returnType, String name, List<String> parameters, List<IStatement> codeBlock){
+        this.classThatContainsMethod = classThatContainsMethod;
+        this.returnType = returnType;
+        this.name = name;
+        this.parameters = parameters;
+        this.codeBlock = codeBlock;
+    }
 
-    public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext, HashMap<String, HashMap<String, String>> typeContext, List<MethodDecl> fieldsOrMethods) throws Exception {
+    public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext, HashMap<String, HashMap<String, String>> typeContext) throws Exception {
         // write localvars
-
-
         // jede methode als block statement aufrufen
         return null;
     }
diff --git a/Source/abstractSyntaxTree/Class/RefType.java b/Source/abstractSyntaxTree/Class/RefType.java
index 3018ec7..0b5f977 100644
--- a/Source/abstractSyntaxTree/Class/RefType.java
+++ b/Source/abstractSyntaxTree/Class/RefType.java
@@ -2,15 +2,10 @@ package abstractSyntaxTree.Class;
 
 import TypeCheck.AbstractType;
 import TypeCheck.TypeCheckResult;
-import abstractSyntaxTree.Class.FieldDecl;
-import abstractSyntaxTree.Class.MethodDecl;
-import abstractSyntaxTree.Datatype.IDatatype;
-import abstractSyntaxTree.Program;
-import jdk.jshell.spi.ExecutionControl;
 import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 
@@ -19,37 +14,56 @@ public class RefType extends AbstractType implements IClass {
     public String name;
     public List<FieldDecl> fieldDecls;
     public List<MethodDecl> methodDecls;
-    private HashMap<String, HashMap<String, String>> typeContext; // (class, (type, identifier))
-    public HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext; // (class, (returntype, (identifier, parameter)))
     private boolean hasMain;
 
-    public RefType(List<FieldDecl> fieldDecls,
+    public RefType(String name,
+                   List<FieldDecl> fieldDecls,
                    List<MethodDecl> methodDecls,
-                   HashMap<String, HashMap<String, String>> typeContext,
-                   HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext, String name){
+                   boolean hasMain
+                   ){
         this.name = name;
         this.fieldDecls = fieldDecls;
         this.methodDecls = methodDecls;
-        this.typeContext = typeContext;
-        this.methodContext = methodContext;
+        this.hasMain = hasMain;
     }
 
-
-
-    @Override
     public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, List<String>>>> methodContext,
-                                     HashMap<String, HashMap<String, String>> typeContext, List<MethodDecl> fieldsOrMethods) throws Exception {
+                                     HashMap<String, HashMap<String, String>> typeContext) throws Exception {
         TypeCheckResult result = new TypeCheckResult();
 
+        // check if field with the same identifier is defined more than once
+        List<String> discoveredFieldIdentifiers = new ArrayList<>();
         for (FieldDecl fieldDecl : fieldDecls) {
-            fieldDecl.typeCheck(fieldDecls);
+            if(discoveredFieldIdentifiers.contains(fieldDecl.identifier)){
+                throw new Exception("A field with the identifier " + fieldDecl.identifier + " was defined more than once in the same class.");
+            }
+            discoveredFieldIdentifiers.add(fieldDecl.identifier);
         }
 
+        // typecheck each field
+        for (FieldDecl fieldDecl : fieldDecls) {
+            fieldDecl.typeCheck(typeContext);
+        }
+
+
+        // check if any methods have the same name and return type (overloaded methods are not allowed here)
+        HashMap<String, String> discoveredMethods = new HashMap<>(); // returntype, identifier
         for (MethodDecl methodDecl : methodDecls) {
-            methodDecl.typeCheck(methodContext, typeContext, methodDecls);
+
+            if (discoveredMethods.containsKey(methodDecl.returnType)) {
+                if(discoveredMethods.get(methodDecl.returnType).equals(methodDecl.name)){
+                    throw new Exception("A method with the name " + methodDecl.name + " and return type " + methodDecl.returnType + " was defined more than once in the same class.");
+                }
+            }
+           discoveredMethods.put(methodDecl.returnType, methodDecl.name);
         }
 
-        result.type = "class";
+        // type check each method
+        for (MethodDecl methodDecl : methodDecls) {
+            methodDecl.typeCheck(methodContext, typeContext);
+        }
+
+        result.type = this.name;
         setTypeCheckResult(result);
         return result;
     }
diff --git a/Source/abstractSyntaxTree/Program.java b/Source/abstractSyntaxTree/Program.java
index 659ad47..792d689 100644
--- a/Source/abstractSyntaxTree/Program.java
+++ b/Source/abstractSyntaxTree/Program.java
@@ -23,13 +23,15 @@ public class Program {
 
     public Program(List<RefType> classes){
         this.classes = classes;
-        this.typeContext = new HashMap<>();
-        this.methodContext = new HashMap<>();
     }
 
 
     public TypeCheckResult typeCheck() throws Exception{
         for(RefType oneClass : classes){
+
+            // build type context
+            this.typeContext = new HashMap<>();
+
             HashMap<String, String> classVars = new HashMap<>();
             for (FieldDecl fieldDecl: oneClass.fieldDecls){
                 classVars.put(fieldDecl.type, fieldDecl.identifier);
@@ -42,10 +44,10 @@ public class Program {
                 methodIdentifierAndParameter.put(methodDecl.name, methodDecl.parameters);
                 returnTypeAndMethod.put(methodDecl.returnType, methodIdentifierAndParameter);
             }
-
+            this.methodContext = new HashMap<>();
             methodContext.put(oneClass.name, returnTypeAndMethod);
 
-            oneClass.typeCheck(methodContext, typeContext, oneClass.methodDecls);
+            oneClass.typeCheck(methodContext, typeContext);
         }
         return null;
     }