1.as...as,You are as tall as your friend.2.for oneself,You can buy a new pen for yourself.
3.by oneself,'He finished it by himself.4.say to oneself,The old man often says to himself at home.
5,help oneself to,Please help yourself to some tea.6.teach oneself...I teach myself English every day.
7,enjoy oneself,Did your enjoy yourself in the park yesterday?