七年级主要短语及用法
1. be interest ed in doing sth. = be keen on doing sth.
对做某事感兴趣；热衷于做某事●He is interested in sing ing. = He is keen on sing ing.
●They are interested in danc ing. = They are keen on danc ing.
do ing---表示动词的现在分词（-ing形式）；即在这个短语中，动词必须用现在分词。动词变为ing形式分几大类，具体分类第二单元语法课件里有详细讲解。
●I am interested in play ing basketball. = I am keen on play ing basketball.
●Are you interested in playing the piano? --- No, I am not.
钢琴属于西洋乐器，所以在play后面要加the；而球类运动（如basketball等）则不用
be interest ed in sth.= be keen on sth.
对某物感兴趣；热衷于某物●Fred is interested in sports. = Fred is keen on sports.
●Our teachers are interested in music. = Our teachers are keen on music.
当需要表达的意思是对某物体感兴趣时，不需要加动词，直接加名词或名词短语即可。
2. come from…= be from…来自于......
●She come s from China. = She is from China.
主语是第三人称单数，动词后要加s；句中有be动词时，要用is（过去时用was）
●She doesn’t come from China. = She is not from China.
变为否定句时，要注意句中是否有be动词：
有be动词时，直接在be动词后加not；
没有be动词时，则需添加一个助动词（do / does），然后在助动词后加not.
●Does she come from China? = Is she from China?
变为疑问句时，句子中如果有be动词，就将be动词提到主语前，句尾加问号；
如果没有be动词，则需添加助动词（do / does）并放到句首，同时，句中的动词必须变为原形。（come s→ come）
●This movie was based on a real story.
= This movie was from a real story.
= This movie c a me from a real story.
这部电影是根据一个真实故事改编的。（这部电影来自一个真实的故事）be based on...意思是“以...为基础”；
在例句的这种情况中，可以用be from和come from来替换。（其它时候不可以替换）电影的改编过程，通常都是已经完成的事情，所以大多用过去式。
be动词的过去式为was, were；动词过去式大部分直接加ed，但也有少数特殊变化。
●Was this movie based on a real story?
= Was this movie from a real story? = Did this movie come from a real story?
变为疑问句时，特别要注意动词的时态；动词过去式决定助动词必须用did.
3. pass sb. sth. = pass sth. to sb. 把某物(sth.)传/递给某人(sb.)
●Can you pass me the cup please? = Can you pass the cup to me please?
Can意思是“能够”，属于情态动词。
只要有情态动词，动词永远都用原形，不再受主语影响
●Tom pass ed his brother a pen just now.
= Tom pass ed a pen to his brother just now.
just now意为“刚才”，说明句子是过去时，所以动词要变过去式
●Did Tom pass his brother the pen just now?
= Did Tom pass the pen to his brother just now?
过去时，句中没有“be动词”，变疑问句时要用“助动词”did
4. each other = one an other 彼此，互相
●We always help each other. = We always help one another.
句中有频率副词always，表示习惯性的动作，说明句子是一般现在时
主语不是第三人称单数，所以动词用原形
频率副词（由高至低排列）：always → usually → often → sometimes → seldom → never
总是通常经常有时候很少从不
●Do trees often communicate with each other?
= Do trees often communicate with one another?
句中有频率副词often，说明这是一般现在时的句子
主语不是第三人称单数，所以动词用原形
句中没有be动词，变疑问句时要用助动词do
●They trusted each other two years ago. = They trusted one another two years ago.
句中有表示时间的短语two years ago，说明这是过去时的句子，动词trust要变过去式●Did they trust each other two years ago? =Did they trust one another two years ago? 过去时的句子，句中没有be动词时，变疑问句时要用助动词did
5. Why not do sth. ? = Why don’t you do sth. ? 不如......（提建议）
●Why not walk to school? = Why don’t you walk to school?
这两个句子的共同点在于，动词都要用原形；
而不同点也很明显，Why not后面直接加动词，但是如果是Why don’t，则必须要加上对于听取这条建议的人的称呼，即例句中的you，然后再加动词。
6. be famous for... = be well-know n for... 以......而闻名
●Beijing is famous for the Great Wall. = Beijing is well-known for the Great Wall.
这两个短语之所以意思相同，仅仅是因为famous和well-known这两个单词意思相同；而短语里的其他部分（be动词和介词for）是完全不变的。
注意well-known的拼写，这是一个独立的单词，中间的短横线“-”一定要写上！
7. offer sb. sth. = offer sth. to sb.
= provide sth. for sb. = provide sb. with sth.
为某人提供某物●Our school offer s us books and classrooms.
= Our school offer s books and classrooms to us.
