1.(主語+過去時） I went to Beijing last year.He came back home at 6 o'clock.We studied History last year.You bought this for me as a present last year.I posted a letter to my friend.2.(主語+ have + 過去分詞） I have been to Beijing.He has completed his university study.They have arrived home safe and sound.She has got the job.You have told me that before.3.(主語+was/were+v-ing) I was writing a letter at 8 o'clock yesterday evening.( She was watching TV when I got there.The teacher was telling a story when Ming went in the classroom.It was raining at that time.They were playing football at 3 o'clock yesterday afternoon.