diff --git a/build/build.go b/build/build.go
index cafe0c7..425bbab 100644
--- a/build/build.go
+++ b/build/build.go
@@ -47,7 +47,7 @@ func (sp *SourceProgram) Build(backend asm.Backend, emitAsmOnly bool, toPrint To
 	id := 0
 
 	addRootNode := func(task task) int {
-		l.Debugf("registering root task %d", id)
+		l.Debugf("registering root task %d %q", id, task.Name())
 		node := &node{task: task}
 		nodes[id] = node
 		rootNodes = append(rootNodes, id)
@@ -56,7 +56,7 @@ func (sp *SourceProgram) Build(backend asm.Backend, emitAsmOnly bool, toPrint To
 	}
 
 	addNode := func(task task, deps ...int) int {
-		l.Debugf("registering task %d", id)
+		l.Debugf("registering task %d %q", id, task.Name())
 		if len(deps) <= 0 {
 			panic("node without dep is useless")
 		}
diff --git a/build/task.go b/build/task.go
index aa6805c..ee4e9d0 100644
--- a/build/task.go
+++ b/build/task.go
@@ -260,8 +260,8 @@ func runTasks(nodes map[int]*node, rootNodes []int, l *utils.Logger) error {
 		if done[id] != notStarted {
 			panic(fmt.Sprintf("tried starting task %d twice", id))
 		}
-		l.Debugf("executing task %d", id)
 		node := nodes[id]
+		l.Debugf("executing task %d %q", id, node.task.Name())
 		output[id] = &strings.Builder{}
 		go node.task.Run(id, output[id], doneChan)
 		running = append(running, id)
@@ -299,7 +299,7 @@ func runTasks(nodes map[int]*node, rootNodes []int, l *utils.Logger) error {
 	for !allFinished {
 		select {
 		case result := <-doneChan:
-			l.Debugf("task %d is done with err: %v", result.Id, result.Err)
+			l.Debugf("task %d %q is done with err: %v", result.Id, nodes[result.Id].task.Name(), result.Err)
 			for i, id := range running {
 				if id == result.Id {
 					running = slices.Delete(running, i, i+1)
diff --git a/design.md b/design.md
new file mode 100644
index 0000000..95ae87c
--- /dev/null
+++ b/design.md
@@ -0,0 +1,18 @@
+# Designs
+
+Playground for language design dessisions
+
+## Function Calls
+
+```tt
+fn hi(hello: i32) = {
+    3
+};
+
+fn main() = {
+    hi!;
+    hi();
+    hi;
+};
+
+```
diff --git a/language.md b/language.md
index 839dc05..67b167b 100644
--- a/language.md
+++ b/language.md
@@ -3,9 +3,8 @@
 ## Syntax
 
 ```tt
-// Return type is i64
 fn main() = {
-    i : = 3;
+    i := 3;
     i
 };
 ```
diff --git a/parser/parser.go b/parser/parser.go
index fea2462..475ca0d 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -192,6 +192,9 @@ func (p *Parser) parseArgumentList() ([]ast.Argument, bool) {
 	for p.peekTokenIs(token.Ident) {
 		p.nextToken()
 		name := p.curToken.Literal
+		if ok, _ := p.expectPeek(token.Colon); !ok {
+			return args, false
+		}
 		p.nextToken()
 		t, ok := p.parseType()
 
diff --git a/test.tt b/test.tt
index bbeb911..588b55f 100644
--- a/test.tt
+++ b/test.tt
@@ -1,13 +1,17 @@
 fn main() = {
-    hi := 4;
+    i := 5;
 
-    if hi == 4 {
-        test2 := 3;
-        hi = 0 
+    if i == 5 {
+        0
+    } else {
+        1
     }
-    else {
-        hi = 1
-    };
 };
 
-fn test2() = {};
+fn test2(hello: i32,) = {
+    hello
+};
+
+fn test2(hello: i32,) = {
+    hello
+};
diff --git a/todo.md b/todo.md
index 8b1aeaf..64ef373 100644
--- a/todo.md
+++ b/todo.md
@@ -1,3 +1,4 @@
 - [ ] Fix inconsensity in asm, change all structs to pointer
 - [ ] Fix inconsensity in Tests
 - [ ] Find a better way todo tests, like to generate a test case
+- [ ] Add packages
diff --git a/typechecker/variable_resolution.go b/typechecker/variable_resolution.go
index a5f6481..9e2bcac 100644
--- a/typechecker/variable_resolution.go
+++ b/typechecker/variable_resolution.go
@@ -73,6 +73,11 @@ func VarResolve(p *ast.Program) (map[string]Scope, error) {
 	for _, d := range p.Declarations {
 		switch d := d.(type) {
 		case *ast.FunctionDeclaration:
+			_, ok := functionToScope[d.Name]
+			if ok {
+				return functionToScope, errorf(d.Token, "duplicate function name %q", d.Name)
+			}
+
 			s := Scope{Variables: make(map[string]Var)}
 			for _, arg := range d.Args {
 				s.SetUniq(arg.Name)