yesterday的过去式是什么

yesterday是时间副词，也可用作名词，它没有过去式，它属于过去式的标志词。如：

I read an interesting book yesterday.我昨天看了一本很有意思的书。

He was playing basketball on yesterday morning.他昨天上午在打篮球。

He arrived in Singapore yesterday.他昨天到了新加坡。

yesterday不是动词，没有过去式，例如：

1.That isn't quite square with what you said yesterday.这跟你昨天所讲的不大吻合。

2.Government sources indicated yesterday that cuts may have to be made.***方面昨天透露，削减可能势在必行。

3.He made all the right noises at the meeting yesterday.在昨天的会上，他的话句句都合大家的胃口。

yesterday is a noun.no past tence for it ! past tense is used for verb !。