⑴.将时间状语改为时间段 + ago,句中谓语动词用一般过去时.
My brother joined the army two years ago.
⑵.若保留for+时间段,since+时间点/从句, 或用在 how long 句型中,则需将终止性动词改为相应的状态动词或延续性动词
对应关系
come/go/arrive/get/reach/move------be in/at
join the army----be in the army be a soldier
join the Party----be in the Party be a Party member
catch a cold-----have a cold
例
They borrowed the book two weeks ago.→ They have kept the book for two weeks.
A month has passed since he left home. → He has been away from home for a month.