一變：肯定句變為否定句

【技巧1】當句中含有情態動詞或助動詞could，would，should等時，可直接在其后面加not構成否定句。例如：

I could get you a concert ticket. → I could not / couldn’t get you a concert ticket.

【技巧2】當句中含有系動詞was，were 時，可直接在其后加not構成否定句。例如：

I was on the Internet when you called me. → I was not / wasn’t on the Internet when you called me.

【技巧3】當句中謂語是除情態動詞、助動詞、系動詞was,were以外的動詞時，在該動詞之前加did not / didn’t，動詞還原，構成否定句。例如：

The famous singer sang some Chinese songs. → The famous singer did not / didn’t sing any Chinese songs.

二變：陳述句變為一般疑問句

【技巧1】移動詞語的位置。將was，were,could，would，should等移到句首。例如：

He could pack his things himself. → Could he pack his things himself?

【技巧2】添加助動詞did。謂語是除情態動詞、助動詞、系動詞was,were以外的動詞時，在主語之前加did，動詞還原。例如：

Mr Li looked very old. → Did Mr Li look very old?

三變：陳述句變為特殊疑問句

【技巧1】確定疑問詞：人who / whom，物what，地點where，時間when / what time，原因why，頻率how often，長度how long，距離how far等等。例如：

They gave the concert last night. → When did they give the concert?

【技巧2】辨認結構形式：疑問詞+情態動詞/助動詞/ was / were / did +主語+...? 例如：

The accident happened near the station. → Where did the accident happen