1、“open”的意思是：adj.敞开的，开着的;公开的，公共的;坦率的;有议论余地的。vt.&vi.(打)开;开始;睁开;启动。n.公开;户外，野外;空旷。vi.使打开;展示，显现。vt.开放;张开;开张营业;为(建筑物)揭幕。

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.

二变：陈述句变为一般疑问句

【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