托福考试中单复数不同的单词
托福考试中的语法部分经常会有一些不显眼的意思相近小词作为考点，归纳一下考前必浏览一下的几个小词组群，必会让你事半功倍。
like / as
like 是介系词，必须接名词。
as 是连接词，必须接子句。
She sings like an angel.
She sings as an angel does.
due to / because of / because / for / since / as
due to 接受词，通常放在 be 动词之后。
His absence was due to illness.
because of 因为有介系词，必须接受词。
He canceled his reservation because of his cold.
because 作连接词，叙述理由，要接子句。
I don ’ t go to school because I had a bad headache.
for 作连接词，推测前句的理由，要接子句，但不能放在句首。
He was glad to go, for his grandmother had been good to him.
since 是连接词，语意没有 because 那么强，置于句首。
Since you are going to go to the post office, would you mail this letter ? （既然你要去邮局，可以帮我寄这封信吗？）
as 作连接词，语意比 since 更弱。
As it was getting dark, we made for home.
compare to / compare with
compare to （比喻、比作），作抽象事物之间的比较，而 compare with 则作一般事物的比较。
I should compare your eyes to diamonds.
我应该把你的眼睛比喻成钻石。
We can ’ t compare diamond with jade.
我们无法比较钻石和翡翠。
imply / infer
imply 是暗示、暗寓的意思 ， infer 则是由暗示、暗寓来推测结论。
The guest speaker implied that the scholar ’ s theory was wrong.
The fact may be inferred from his words.
watch / look / see
watch 是看着动态的景物， look 是看着静态的景物， see 则广义地用于看见人或物
I am watching a baseball game/TV.
Look at the picture on the wall.
I can see some roses in the vast.
scarcely /rarely /seldom / seldom, if ever / hardly ever
scarcely, rarely, seldom 和 hardly 放在句首时，主词和 be 动词或助动词要倒装。
seldom 和 rarely 是“很少”的意思，通常置于动词之前。
She had seldom [or rarely] written to her friend.
seldom if ever 和 hardly ever 是副词片语，意思皆为“几乎不… . ”。
He seldom, if ever, drinks.
He hardly ever drinks.
kind of
this kind of + 单数名词 = these kind of + 复数名词，都指只有一个种类。 these kinds of 才指有很多种类
This kind of man is dangerous. = These kind of men are dangerous. （这种人很危险。）
These kinds of trees are easy to grow. （这些品种的树很容易长。）
by / till
by 表示未来将完成的某一时间界限。
—— ｜——————｜———— I will finish my paper by tomorrow.
现在 完成的时点
till 是表继续动作的终点
∨ ∨
ˉˉˉˉˉˉˉˉˉˉ继续ˉˉˉˉˉˉˉˉˉˉˉˉˉˉ I will be here till tomorrow.
现在——————→
线段终点