1. School is open 与 the school is open ：
school is open 是指学校开学 ，这里的 open 是形容词， school 前面不加冠词 the ，意味整个中小学的 school system 。但 the school is open ，多指学校的建筑物开放着，但没学生上课。
同理： He goes to school. 是指他去上学念书受教育，而 He goes to the school. 又指他去学校的建筑物（看朋友、参观等）。
但 The store is open. 是指店在营业中（ = Business is going on. ），而 The store is closed. 又是指店暂时不营业。倘若店是永久性的关门大吉，就应该说： The store was closed down.
不过 closed 当形容词时，又有守旧（ conservative ）或受某种限制（ restricted ）的意思。 比如：
This is a closed community. （这是一个守旧的社区。）（因为宗教信仰等缘由，美国有些社区不欢迎外来的人。）
2. Thick skin 与 thin skin ：
thick skin 是指一个人不害臊，冷静，好脾气 ，但 thin skin 是指非常敏锐 ，易发怒，易激动的人。 比如：
He has thin skin.
= He is thin-skinned .
Many American politicians are very thick-skinned.
thick skin 不是咱们中国人所谓厚脸皮不要脸的意思。对老外来讲，总是还是一种恭维呢！而 thin skin 恰好又相反。
3. To turn the tables 与 under the table ：
turn the tables 意思是扭转局面，作出反击或反告（ to turn around or to reverse the accusation1 toward accuser ），但 under the table 是指做贿赂等违法的事情（ do something illegal ）。 比如：
In court she turned the tables of prosecution2 toward him. （在法院她反而控告他。）
Some politicians accepted brides under the table. （一些政客违法地同意贿赂。）
4. To be attracted to 与 to be attracted by ：
这都是指被吸引住，不过介系词用 to 时，后面一般不说理由，但介词用 by 时，后面多半说明吸引是什么原因。 比如：
She was attracted to him. （她被他吸引住。）（但没说明缘由 ）
= She found herself attracted to him.
= He attracted her. ; 说白些，就是
= She liked him.;
同理 He was attracted to her.
= He found himself attracted to her.
= She attracted him.; 也就是：
= He liked her.
但假如说：
She was attracted by his good-look.
He was attracted by her beauty .
就是由于用 by 时，后面多半都说明吸引的原因。
5. Talk back to 与 turn back on ：
to talk back to someone 意思是对某人回嘴（ to defy ），多半指孩子。而 to turn ones back on someone 系指不喜欢某人（ dislike someone ）。比如：
the boy talks back to his mother all the time. （这男生对他妈妈总是回嘴。）
至于 to be on （ ones ） back about （ something ）又有对某事唠叨 的意思。 比如：
His mother is always on his back about diet. （他母亲常为了饮食对他唠叨。）