Present Tenses

Present Simple

- 講述事實(shí)，周期性的事

- he/she/it 加 s，I/you/we/they不加s

Present Continuous

- 講述還在做，未完成的事

- is/am/are +ing

Present Perfect

- 講述事情的結(jié)果

- has/have+past participle

Present Perfect Continuous

- 講述在之前發(fā)生了，現(xiàn)在還在做的事

- has/have+been+ing

Past Tenses

Past Simple

- 過去發(fā)生的事，完成了(when)

- +d/ed

Past Continuous

- 當(dāng)時情況，原開始發(fā)生的事(while)

- was/were+ing

Past Perfect

- 先發(fā)生的事

- had+pp

Past Perfect Continuous

-連續(xù)性地做事

-had been+ing