Question

1.by bus 用过去式怎么说?

Answer 1

1

by bus 没有过去式,by bus 是介词啊,不是动词,变过去式直接跟上（不用变）就可以了

比如I go to school by bus.变过去时就是

I went to school by bus 变的只是go

因为go是动词,而by bus 就不用变了

2

不用加

比如What did you want?

want就不用加ed了

至于did some washing是do some washing变过来的

变的也只是do