16种，常用9种

常用的：

一般现在时 do/does

一般过去时 did

一般将来时 will do/be going to do...

过去将来时 would/shoud do

现在进行时 be doing

过去进行时 was/were doing

现在完成时 have/has done

过去完成时 had done

现在完成进行时 have/has been doing

不常用的：

将来进行时 will/shall be doing

过去将来进行时 would/should be doing

将来完成时 will/shall have done

过去将来完成时 would/should have done

过去完成进行时 had been doing

将来完成进行时 will/shall have been doing

过去将来完成进行时 would/should bave been doing