diff --git a/parser/tree-tostring.go b/parser/tree-tostring.go
index 7135f0f..a46da08 100644
--- a/parser/tree-tostring.go
+++ b/parser/tree-tostring.go
@@ -124,7 +124,7 @@ func (phrase *Phrase) ToString (indent int, breakLine bool) (output string) {
 func (argument *Argument) ToString (indent int, breakLine bool) (output string) {
 	if !breakLine { indent = 0 }
 
-	switch argument.what {
+	switch argument.kind {
 	case ArgumentKindPhrase:
 		output += doIndent (
 			indent,
diff --git a/parser/tree.go b/parser/tree.go
index ea81d24..7919bde 100644
--- a/parser/tree.go
+++ b/parser/tree.go
@@ -57,9 +57,7 @@ type Type struct {
 type Declaration struct {
 	location file.Location
 	name     string
-	
-	what  Type
-	value []Argument
+	what     Type
 }
 
 // ObjectAttribute represents a notation to initialize object attributes. It
@@ -134,7 +132,7 @@ const (
 // allows things like phrases being arguments to other phrases.
 type Argument struct {
 	location file.Location
-	what     ArgumentKind
+	kind     ArgumentKind
 	value    any
 	// TODO: if there is an argument expansion operator its existence should
 	// be stored here in a boolean.