1.alter常表示局部或表面的改变或变动,改变的范围或程度较小,而本质特性并未发生变化。
2.alter可用作不及物动词,也可用作及物动词,用作及物动词时,接名词或代词作宾语。

alter to〔into〕(v.+prep.)
改变为,更改为 become different; change; make sth different
▲alter sth to〔into〕 sth
We have to alter the house into a barn.我们不得不把房子改建成谷仓。
The bright boy altered it to a circular form.这个聪明的男孩把它改成了圆形。

用作不及物动词
▲S+～(+A)
My opinion on that question has never altered.我对那个问题的看法始终没有改变过。
He has altered not very obviously.他的变化不算很大。
She has altered much older than before.她变得比以前更老了。
His appearance has altered a great deal.他的容貌变了许多。
As times alter, men's affections change.时过境迁。
用作及物动词
▲S+～+n./pron.
She is trying to alter the coat.她正设法改那件衣服。
He alters his face suddenly.他突然变了脸。
The little boy altered his behaviour.这个小男孩儿改变了态度。
The plane altered course.飞机改变了航向。
But nothing can alter the facts.但是事实是改变不了的。
Measures must be taken to alter the situation.必须采取措施来改变目前的情况。
The tailor can alter your new coat to fit you.裁缝会将你的新上衣改得合你的身的。
Eaker would alter his behaviour to make you satisfy.埃克会改变他的行为而令你高兴的。
◇ 用于be ～ed结构
The arrangement can be altered at any time.这一安排随时可以改变。

alter, become, change, convert, modify, turn, vary
参见become条。