diff --git a/AST.py b/AST.py
index c5a1ebc..912616a 100644
--- a/AST.py
+++ b/AST.py
@@ -1,8 +1,9 @@
 from enum import Enum
 
 class Node:
-    def __init__(self):
-        self.children = []            
+    def __init__(self, pos):
+        self.children = []
+        self.pos = pos
         
     def __repr__(self):
         return self.__str__()
@@ -11,7 +12,7 @@ class Node:
         return len(self.children)
         
     def __getitem__(self, index):
-        return self.children[index]
+        return self.children[index]        
     
     def append(self, node):
         self.children.append(node)
@@ -21,36 +22,38 @@ class Node:
 
 class Program(Node):
     def __init__(self):
-        Node.__init__(self)        
+        Node.__init__(self, (-1, -1))        
     
     def __str__(self):
         return "Program:\n" + "\n".join([str(e) for e in self.children])
     
 
 class BlockNode(Node):
-    def __init__(self):      
-        Node.__init__(self)              
+    def __init__(self, pos):      
+        Node.__init__(self, pos)              
     
     def __str__(self):
         return "B{\n" + "\n".join([str(e) for e in self.children]) + "\n}"
 
 
 class ListNode(Node):
-    def __init__(self):
-        Node.__init__(self)              
+    def __init__(self, pos):
+        Node.__init__(self, pos)              
     
     def __str__(self):
         return "@(" + ", ".join([str(e) for e in self.children]) + ")"      
         
 class IdentifierNode(Node):
-    def __init__(self, identifier):        
+    def __init__(self, identifier, pos): 
+        Node.__init__(self, pos)   
         self.identifier = identifier
     
     def __str__(self):
         return f"L'{self.identifier}'"
         
 class AssignExpression(Node):
-    def __init__(self, target, value):        
+    def __init__(self, target, value, pos):
+        Node.__init__(self, pos)           
         self.target = target
         self.value = value
         
@@ -58,7 +61,8 @@ class AssignExpression(Node):
         return f"A[{self.target} = {self.value}]"
    
 class AsteriskStatementNode(Node):
-    def __init__(self, iterator, statement):        
+    def __init__(self, iterator, statement, pos):
+        Node.__init__(self, pos)   
         self.iterator = iterator
         self.statement = statement
         
@@ -66,7 +70,8 @@ class AsteriskStatementNode(Node):
         return f"*({self.iterator}: {self.statement})"
    
 class ColonNode(Node):
-    def __init__(self, a, b):        
+    def __init__(self, a, b, pos):
+        Node.__init__(self, pos)   
         self.a = a
         self.b = b
         
@@ -74,33 +79,40 @@ class ColonNode(Node):
         return f":({self.a}, {self.b})"
    
 class ExpressionNode(Node):
+    def __init__(self, pos):
+        Node.__init__(self, pos)   
+        
     def __str__(self):
         return f"{self.__class__.__name__}('{self.value}')"
 
 
 class IntegerLiteralNode(ExpressionNode):
-    def __init__(self, value):        
+    def __init__(self, value, pos):
+        Node.__init__(self, pos)   
         self.value = value        
     
     def __str__(self):
         return f"i'{self.value}'"
 
 class StringLiteralNode(ExpressionNode):
-    def __init__(self, value):        
+    def __init__(self, value, pos):
+        Node.__init__(self, pos)   
         self.value = value
 
     def __str__(self):
         return f"s'{self.value}'"
     
 class NoteLiteralNode(ExpressionNode):
-    def __init__(self, value):        
+    def __init__(self, value, pos):
+        Node.__init__(self, pos)   
         self.value = value
         
     def __str__(self):
         return f"n'{self.value.note}[{self.value.octave}, {self.value.duration}]'"
 
 class FunctionCallNode(Node):
-    def __init__(self, identifier, arguments):        
+    def __init__(self, identifier, arguments, pos):
+        Node.__init__(self, pos)   
         self.identifier = identifier
         self.arguments = arguments
         
@@ -108,11 +120,14 @@ class FunctionCallNode(Node):
         return f"F({self.identifier}: {self.arguments})"
 
 class CommaNode(Node):    
+    def __init__(self, pos):
+        Node.__init__(self, pos)   
     def __str__(self):
         return "[,]"
 
 class PercentNode(Node):
-    def __init__(self, value):        
+    def __init__(self, value, pos):        
+        Node.__init__(self, pos)   
         self.value = value
         
     def __str__(self):
diff --git a/Environment.py b/Environment.py
index d7ff598..49efdd1 100644
--- a/Environment.py
+++ b/Environment.py
@@ -1,9 +1,10 @@
 import sys
-from Evaluator import RuntimeException, objectString
+from Evaluator import objectString
 from Note import *
 import random
 import Synth
 import time
+from Error import RuntimeException
 
 types = {
     int: 'integer',
@@ -28,7 +29,7 @@ class Environment():
                         return value         
                 else:
                     return value
-        raise RuntimeException(f"Variable '{name}' is not declared" + ("" if type is None else f" (expected type: {types[type]})"))
+        raise RuntimeException(None, f"Variable '{name}' is not declared" + ("" if type is None else f" (expected type: {types[type]})"))
     
     def findVariableScope(self, name, type=None):
         for scope in reversed(self.scopes):
diff --git a/Error.py b/Error.py
index 831cca9..c1b588e 100644
--- a/Error.py
+++ b/Error.py
@@ -1,2 +1,9 @@
-class ParseError(Exception):
-    pass
+class SyntaxException(Exception):
+    def __init__(self, pos, msg):        
+        posStr = "" if pos is None else f"[line {pos[0]+1}, col {pos[1]+1}]"        
+        self.msg = f"Syntax error {posStr}:\n{msg}"
+    
+class RuntimeException(Exception):
+    def __init__(self, pos, msg):
+        posStr = "" if pos is None else f"[line {pos[0]+1}, col {pos[1]+1}]"        
+        self.msg = f"Syntax error {posStr}:\n{msg}"
diff --git a/Evaluator.py b/Evaluator.py
index e086752..7346ea2 100644
--- a/Evaluator.py
+++ b/Evaluator.py
@@ -2,9 +2,7 @@ from Tokenizer import tokenize, TokenType
 from Parser import parse
 from AST import *
 from Note import Note
-
-class RuntimeException(Exception):
-    pass
+from Error import RuntimeException
 
 def evaluateProgram(program, environment):
     for node in program.children:
@@ -39,8 +37,8 @@ def objectString(obj):
     if isinstance(obj, float):
         return f"{int(obj*100)}%"
     if obj is None:
-        raise RuntimeException(f"Trying to interpret void")
-    raise RuntimeException(f"Don't know how to interpret {str(obj)}")
+        raise RuntimeException(None, f"Trying to interpret void")
+    raise RuntimeException(None, f"Don't know how to interpret {str(obj)}")
 
 def evaluateNote(note, environment):
     return note.value
@@ -51,7 +49,7 @@ def evaluateFunctionCall(functionCall, environment):
     for name, definition in environment.functions.items():
         if name == function:
             return definition(arguments, environment)
-    raise RuntimeException(f"Function '{function}' does not exist")
+    raise RuntimeException(functionCall.pos, f"Function '{function}' does not exist")
         
 
 def evaluateComma(comma, environment):
@@ -109,7 +107,7 @@ def evaluateColon(colon, environment):
         return Note.range(colon.a.value, colon.b.value)
     elif isinstance(colon.a, IntegerLiteralNode) and isinstance(colon.b, IntegerLiteralNode):
         return list(range(colon.a.value, colon.b.value+1))
-    raise RuntimeException("Invalid colon arguments")
+    raise RuntimeException(colon.pos, "Invalid colon arguments")
 
 def evaluate(input, environment):
     if isinstance(input, Program):
diff --git a/Note.py b/Note.py
index c46825c..eedd2ed 100644
--- a/Note.py
+++ b/Note.py
@@ -1,6 +1,6 @@
 from enum import Enum
-from Error import ParseError
 import math
+from Error import SyntaxException
 
 class NotePitch(Enum):
     C = 0
@@ -52,7 +52,7 @@ class NotePitch(Enum):
                 }
             return map[string.lower()]
         except KeyError as e:
-            raise ParseError(f"Note '{string}' does not exist")
+            raise SyntaxException(None, f"Note '{string}' does not exist")
 
 class Note:
     def __init__(self, note, octave = 4, duration = 4):        
diff --git a/Parser.py b/Parser.py
index 9f6c053..4520f11 100644
--- a/Parser.py
+++ b/Parser.py
@@ -1,19 +1,22 @@
 from Tokenizer import *
 from Note import *
 from AST import *
-from Error import ParseError
+from Error import SyntaxException
 
 def expectedFound(expected, found):
-    raise ParseError(f"Expected: {expected}, found: {found}")
+    raise SyntaxException(None, f"Expected: {expected}, found: {found}")
 
 def parseInteger(input, parent):
-    return IntegerLiteralNode(int(input.pop(0).value))
+    token = input.pop(0)
+    return IntegerLiteralNode(int(token.value), token.pos)
     
-def parseString(input, parent):    
-    return StringLiteralNode(input.pop(0).value[1:-1])
+def parseString(input, parent):   
+    token = input.pop(0)
+    return StringLiteralNode(token.value[1:-1], token.pos)
     
 def parseNote(input, parent): 
-    value = input.pop(0).value
+    token = input.pop(0)
+    value = token.value
     consumedChars = 1
     notePitch = value[consumedChars]
     consumedChars += 1
@@ -33,21 +36,21 @@ def parseNote(input, parent):
             consumedChars += 1  
             duration = int(durationString)
     
-    return NoteLiteralNode(Note(notePitch, octave, duration))
+    return NoteLiteralNode(Note(notePitch, octave, duration), token.pos)
 
 def parseComma(input, parent):
-    input.pop(0)
-    return CommaNode()
+    token = input.pop(0)
+    return CommaNode(token.pos)
 
 def parseList(input, parent):       
-    input.pop(0)
+    token = input.pop(0)
     
-    node = ListNode()
+    node = ListNode(token.pos)
     
     while input[0].type != TokenType.CLOSE_PAREN:  
         element = parseArrayElement(input, node)
         if element is None:
-            raise ParseError(f"Line: {input[0].pos[0]+1}, col: {input[0].pos[1]+1}: Invalid element '{input[0].value}'")
+            raise SyntaxException(input[0].pos, "Invalid element '{input[0].value}'")
         node.append(element)
     
     if input[0].type != TokenType.CLOSE_PAREN:
@@ -57,9 +60,9 @@ def parseList(input, parent):
     return node
             
 def parseBlock(input, parent):
-    input.pop(0)
+    token = input.pop(0)
     
-    block = BlockNode()
+    block = BlockNode(token.pos)
     
     while input[0].type != TokenType.CLOSE_BRACKET:
         block.append(parseToken(input, block))
@@ -72,62 +75,63 @@ def parseBlock(input, parent):
 
 
 def parseAsterisk(input, parent):
-    input.pop(0)
+    token = input.pop(0)
     
     iterator = parent.pop(-1)
     value = parseStatement(input, parent) #TODO: only statements! (?)
     
-    return AsteriskStatementNode(iterator, value)        
+    return AsteriskStatementNode(iterator, value, token.pos)        
    
 def parseNoteOrColon(input, parent):
     note = parseNote(input, parent)    
     if len(input) > 1 and input[0].type == TokenType.COLON:
-        input.pop(0)                
+        token = input.pop(0)                
         b = parseNote(input, parent) #TODO: only expressions!
         if b is None:
-            raise ParseError(f"Line {input[0].pos[0]+1}, col {input[0].pos[1]+1}: Invalid colon argument '{input[0].value}'")
-        return ColonNode(note, b)
+            raise SyntaxException(input[0].pos, f"Invalid colon argument '{input[0].value}'")
+        return ColonNode(note, b, token.pos)
     
     return note
    
 def parseIntegerOrColon(input, parent):
     integer = parseInteger(input, parent)    
     if len(input) > 1 and input[0].type == TokenType.COLON:
-        input.pop(0)                
+        token = input.pop(0)                
         b = parseInteger(input, parent) #TODO: only expressions!
         if b is None:
-            raise ParseError(f"Line {input[0].pos[0]+1}, col {input[0].pos[1]+1}: Invalid colon argument '{input[0].value}'")
-        return ColonNode(integer, b)
+            raise SyntaxException(input[0].pos, f"Invalid colon argument '{input[0].value}'")
+        return ColonNode(integer, b, token.pos)
     
     return integer   
    
-def parseFunctionCallOrAssignOrIdentifier(input, parent):    
-    identifier = IdentifierNode(input.pop(0).value)
+def parseFunctionCallOrAssignOrIdentifier(input, parent):   
+    token = input.pop(0)
+    identifier = IdentifierNode(token.value, token.pos)
     # Function call
     if len(input) > 0 and input[0].type == TokenType.OPEN_PAREN:            
         arguments = parseList(input, parent)        
-        return FunctionCallNode(identifier, arguments)
+        return FunctionCallNode(identifier, arguments, token.pos)
     # Assign
     if len(input) > 1 and input[0].type == TokenType.ASSIGN:          
-        input.pop(0)            
+        token = input.pop(0)            
         value = parseExpression(input, parent) #TODO: only expressions!
-        return AssignExpression(identifier, value)
+        return AssignExpression(identifier, value, token.pos)
         
     return identifier
 
 def parsePercent(input, parent):
-    input.pop(0)
+    token = input.pop(0)
     
     value = parent.pop(-1)
     
-    return PercentNode(value)
+    return PercentNode(value, token.pos)
 
 def parseMinus(input, parent):
-    input.pop(0)
+    token = input.pop(0)
     
     value = parseInteger(input, parent)
     
-    return IntegerLiteralNode(-value.value)
+    return IntegerLiteralNode(-value.value, token.pos)
 
 def parseExpression(input, parent):    
     type = input[0].type
@@ -145,7 +149,7 @@ def parseExpression(input, parent):
         return parsePercent(input, parent)
     if type == TokenType.OPEN_PAREN:
         return parseList(input, parent)     
-    raise ParseError(f"Line {input[0].pos[0]+1}, col {input[0].pos[1]+1}: Unexpected character '{input[0].value}'")
+    raise SyntaxException(input[0].pos, f"Unexpected character '{input[0].value}'")
  
 def parseArrayElement(input, parent):
     type = input[0].type
@@ -172,20 +176,3 @@ def parse(input):
     while len(input) > 0:
         root.append(parseToken(input, root))
     return root
-
-if __name__ == "__main__":      
-    try:
-        with open(sys.argv[1], 'r') as source:
-            lines = [line.rstrip('\n') for line in source.readlines()]
-            
-        tokens = [token for token in tokenize(lines) if token.type != TokenType.COMMENT]
-        
-        ast = parse(tokens)
-        
-        print(ast)
-    except TokenizerError as e:
-        print(str(e))
-        
-    except ParseError as e:
-        print(str(e))
-    
diff --git a/Tokenizer.py b/Tokenizer.py
index 2426933..dd2799d 100644
--- a/Tokenizer.py
+++ b/Tokenizer.py
@@ -2,6 +2,7 @@ from enum import Enum
 import time
 import re
 import sys
+from Error import SyntaxException
 
 class TokenType(Enum):
     OPEN_PAREN = 1
@@ -19,10 +20,6 @@ class TokenType(Enum):
     COMMENT = 13
     PERCENT = 14
     MINUS = 15
-    
-class TokenizerError(Exception):
-    pass
-    
 
 class Token:
     def __init__(self, type, value, pos):
@@ -188,7 +185,7 @@ def doTokenize(lines):
                     break            
             
             if not tokenized:
-                raise TokenizerError(f"Line {lineNumber+1}, col {current+1}: unknown symbol '{line[current]}'")
+                raise SyntaxException((lineNumber, current), f"Unknown symbol '{line[current]}'")
             
     return [token for token in tokens if token.type is not None]
 
diff --git a/main.py b/main.py
index c96519a..0dc0ff0 100644
--- a/main.py
+++ b/main.py
@@ -2,16 +2,22 @@ from Tokenizer import tokenize
 from Parser import parse
 from Evaluator import evaluate
 from Environment import createEnvironment
+from Error import SyntaxException, RuntimeException
 import sys
 
 if __name__ == "__main__":
-    with open(sys.argv[1], 'r') as source:
-        lines = [line.rstrip('\n') for line in source.readlines()]
-    
-    env = createEnvironment()
-    
-    tokens = tokenize(lines)
-    
-    ast = parse(tokens)
-    
-    evaluate(ast, env)
+    try:
+        with open(sys.argv[1], 'r') as source:
+            lines = [line.rstrip('\n') for line in source.readlines()]
+        
+        env = createEnvironment()
+        
+        tokens = tokenize(lines)
+        
+        ast = parse(tokens)
+        
+        evaluate(ast, env)
+    except SyntaxException as e:
+        print(e.msg)
+    except RuntimeException as e:
+        print(e.msg)