一般现在时 do Sth.
一般过去时 did Sth.
现在进行时 be doing Sht.
过去进行时 was/were doing Sth.
一般将来时 will do Sth.
I am writing.现在进行时
I will write.一般将来时
I wrote yesterday.一般过去时
I write everyday.一般现在时
I was writing yesterday at that time .过去进行时