diff --git a/src/main/antlr/Decaf.g4 b/src/main/antlr/Decaf.g4
index 13e5881..547838e 100644
--- a/src/main/antlr/Decaf.g4
+++ b/src/main/antlr/Decaf.g4
@@ -2,19 +2,21 @@ grammar Decaf;
 
 program : (class)+;
 
-class : PUBLIC? 'class' id '{' (var | meth)* '}';
+class : PUBLIC? 'class' id '{' (field | meth)* '}';
 
-var : type id ';' | type id assignSign expr';';
+field : type id ';';
+localVar : type id ';';
 assignSign : '=' | '+=' | '-=' | '*=';
 returntype : type | VOID;
 type : INT | BOOL | CHAR;
 
-meth : PUBLIC? returntype id '(' params? ')' block | mainmeth;
+meth : PUBLIC? returntype id '(' params? ')' block | mainmeth | constructor;
 mainmeth : PUBLIC 'static' 'void' 'main' '(' 'String[] args' ')' block;
+constructor: PUBLIC? id '(' params? ')' block;
 params : param (',' param)*;
 param : type id;
 
-block : '{' (var | stmt)* '}';
+block : '{' (localVar | stmt)* '}';
 
 stmt : 'if' '(' expr ')' block ('else' block)?  #If
     | 'for' '(' expr ';' expr ';' expr ')' block  #For