diff --git a/statement.go b/statement.go
index 85bf1726..8b682c84 100644
--- a/statement.go
+++ b/statement.go
@@ -57,12 +57,12 @@ type StatementModifier interface {
 	ModifyStatement(*Statement)
 }
 
-// Write write string
+// WriteString write string
 func (stmt *Statement) WriteString(str string) (int, error) {
 	return stmt.SQL.WriteString(str)
 }
 
-// Write write string
+// WriteByte write byte
 func (stmt *Statement) WriteByte(c byte) error {
 	return stmt.SQL.WriteByte(c)
 }
@@ -152,7 +152,7 @@ func (stmt *Statement) Quote(field interface{}) string {
 	return builder.String()
 }
 
-// Write write string
+// AddVar add var
 func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 	for idx, v := range vars {
 		if idx > 0 {
@@ -506,7 +506,6 @@ func (stmt *Statement) clone() *Statement {
 	return newStmt
 }
 
-// Helpers
 // SetColumn set column's value
 //   stmt.SetColumn("Name", "jinzhu") // Hooks Method
 //   stmt.SetColumn("Name", "jinzhu", true) // Callbacks Method