dodoingdonedoesdid这些分别是do的什么时态?
它们不是什么时态,而是动词的几种基本形式.如do是动词原形,doing是现在分词,done是过去分词,did是过去式.
它们是构成动词各种时态的基本要素,例如一般现在时态,通常要用动词原形来表示（例They do their homework every day.他们每天做作业）,但是如果主语是第三人称单数时,动词要用三单现形式（如He does his homework every day.他每天做作业）does是do的第三人称单数现在式形式）；
再如They are doing their homework now.他们正在做作业.（现在进行时态）
He / They did his / their homework yesterday.他（他们）昨天做了作业.（一般过去时态）
He has already done his homework.他已经完成作业了.（现在完成时态）等等.
动词时态的掌握要从时态的意义、构成、结构和常用时间状语等方面来掌握就比较容易了.