2、“open”的动词形式:第三人称单数:opens;现在分词:opening;过去式:opened;过去分词:opened。
一变:肯定句变为否定句
【技巧1】当句中含有情态动词或助动词could,would,should等时,可直接在其后面加not构成否定句。例如:
I could get you a concert ticket. → I could not / couldn't get you a concert ticket.
【技巧2】当句中含有系动词was,were 时,可直接在其后加not构成否定句。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】当句中谓语是除情态动词、助动词、系动词was,were以外的动词时,在该动词之前加did not / didn't,动词还原,构成否定句。例如:
The famous singer sang some Chinese songs. → The famous singer did not / didn't sing any Chinese songs.
【技巧1】移动词语的位置。将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】添加助动词did。谓语是除情态动词、助动词、系动词was,were以外的动词时,在主语之前加did,动词还原。例如:
Mr Li looked very old. → Did Mr Li look very old?
三变:陈述句变为特殊疑问句
【技巧1】确定疑问词:人who / whom,物what,地点where,时间when / what time,原因why,频率how often,长度how long,距离how far等等。例如:
They gave the concert last night. → When did they give the concert?
【技巧2】辨认结构形式:疑问词+情态动词/助动词/ was / were / did +主语+...? 例如:
The accident happened near the station. → Where did the accident happen
一些不规则变化:
do>did see>saw make>made take>took eat>ate
read>read put>put get>got hear>heard feel>felt
is/am---was are---were teach---taught catch---caught
buy---bought go---went come---came become---became等
关键词: open是什么意思 open open意思 过去式 过去式技巧 过去式用法 过去式用途 过去式价值 过去式作用