diff --git a/semantic/semantic.go b/semantic/semantic.go
index 0c93ab4..37831e0 100644
--- a/semantic/semantic.go
+++ b/semantic/semantic.go
@@ -40,18 +40,17 @@ func (s *Semantic) exitScope() {
 }
 
 // declare will keep track of declare variables
-func (s *Semantic) declare(node *ast.VarStatement) {
+func (s *Semantic) declare(name string) {
 	if s.scopeStack.IsEmpty() {
 		return
 	}
 
 	peek, _ := s.scopeStack.Peek()
-	(*peek)[node.Name.Value] = false
+	(*peek)[name] = false
 }
 
 // resolve after a variable been resolve we mark it as resolved.
-func (s *Semantic) resolve(node *ast.VarStatement) {
-	name := node.Name.Value
+func (s *Semantic) resolve(name string) {
 	peek, ok := s.scopeStack.Peek()
 	if !ok {
 		return
@@ -104,21 +103,30 @@ func (s *Semantic) analysis(node ast.Node) ast.Node {
 	case *ast.Identifier:
 		s.expectIdentifierDeclare(node)
 	case *ast.VarStatement:
-		s.declare(node)
+		s.declare(node.Name.Value)
 		if _, ok := node.Value.(ast.Expression); ok {
 			s.analysis(node.Value)
 		}
-		s.resolve(node)
+		s.resolve(node.Name.Value)
 	case *ast.ExpressionStatement:
 		s.analysis(node.Expression)
+	case *ast.PrefixExpression:
+		s.analysis(node.Right)
+	case *ast.InfixExpression:
+		s.analysis(node.Left)
+		s.analysis(node.Right)
 	case *ast.FunctionLiteral:
+		s.newScope()
+		for _, arg := range node.Parameters {
+			s.declare(arg.Value)
+			s.resolve(arg.Value)
+		}
 		s.analysis(node.Body)
+		s.exitScope()
 	case *ast.BlockStatement:
-		s.newScope()
 		for _, b := range node.Statements {
 			s.analysis(b)
 		}
-		s.exitScope()
 	}
 	return node
 }
diff --git a/semantic/semantic_test.go b/semantic/semantic_test.go
index 9c8fe66..feee6ac 100644
--- a/semantic/semantic_test.go
+++ b/semantic/semantic_test.go
@@ -21,6 +21,30 @@ func TestScopeVariable(t *testing.T) {
 		{
 			`function () { var a = true; var b = a; }`,
 		},
+		{
+			`var a = 1`,
+		},
+		{
+			`var a = true`,
+		},
+		{
+			`var a = []`,
+		},
+		{
+			`var a = {}`,
+		},
+		{
+			`function (x) { return x; }`,
+		},
+		{
+			`function () { function (y) { var a = y + 1; } }`,
+		},
+		{
+			`function () { var a = -1; }`,
+		},
+		{
+			`function () { var a = !true; }`,
+		},
 	}
 
 	for i, tt := range tests {
@@ -43,6 +67,10 @@ func TestScopeVariablesWrong(t *testing.T) {
 			`function () { var a = a; }`,
 			"Can't read local variable \"a\" in its own initializer IDENT at [Line: 1, Offset: 24]",
 		},
+		{
+			`function () { var a = a + 1 }`,
+			"Can't read local variable \"a\" in its own initializer IDENT at [Line: 1, Offset: 24]",
+		},
 		{
 			`function () { var a = [1, b]; }`,
 			"Variable \"b\" not declare yet IDENT at [Line: 1, Offset: 28]",
@@ -75,6 +103,18 @@ func TestScopeVariablesWrong(t *testing.T) {
 			`function () { var a = "local"; function () { var a = a; } }`,
 			"Can't read local variable \"a\" in its own initializer IDENT at [Line: 1, Offset: 55]",
 		},
+		{
+			`function () { var a = "local"; function () { function () { var a = a; } } }`,
+			"Can't read local variable \"a\" in its own initializer IDENT at [Line: 1, Offset: 69]",
+		},
+		{
+			`function () { function (y) { var a = x + 1; } }`,
+			`Variable "x" not declare yet IDENT at [Line: 1, Offset: 39]`,
+		},
+		{
+			`function () { var a = !x; }`,
+			`Variable "x" not declare yet IDENT at [Line: 1, Offset: 25]`,
+		},
 	}
 
 	for i, tt := range tests {