alter

alter, become, change, convert, modify, turn, vary

这组词共同的意思是“改变”“变化”。change和alter有时可以互换。例如:
Whatever we do, we can't change〔alter〕 the facts.不管我们做什么,我们总不能改变事实。
He has changed〔altered〕 a lot since I last saw him.自从上次见面到现在,他变了很多。
The weather changes〔alters〕 almost daily.天气差不多天天在变。
它们的区别是：
1.change在这几个词中是最普遍、最不正式的一个,可用于任何变化的过程,而不论变化的性质和程度; alter指局部的、表面的、轻微的“改变”“改动”,修改后仍基本上保持原状; alter和convert都指形式和用途上的局部微小改变; turn指彻底改变,以至面目全非,且常用于朝坏的方向改变; modify指限定在一定范围内的修改或修饰,以使之更完美; vary则指事物或其一部分暂时地或反复地变化,从而使事物各部分呈现不同外貌和特点。例如:
When matter changes to a substance different from what it was, the change is a chemical change.当物质变成和原来不同的物质时,这种变化是化学变化。
The plan is O.K. at large, but I suggest it be altered.该计划总的来说是可以的,但我建议做进一步修改。
Pressure varies directly with temperature and inversely with volume.压力随温度成正比例变化,与容积成反比例变化。
All the bank bill was converted into cash.所有的银行票据都兑换成了现金。
Those who were once for him have turned against him.那些原来支持他的人现在转而反对他。
The newspaper turned against the president.该报转而攻击总统。
After he left the university, he became a teacher, but he later turned to translation.他大学毕业后当了教师,但后来转向翻译工作。
2.convert可指改变信仰,尤其是宗教信仰; modify指态度变温和。例如:
He has converted from Buddhism to Catholicism.他已放弃佛教改信天主教了。
You'd better modify your tone.你最好缓和一下你的口气。
He will have to modify his views if he wants to be elected.他如果想当选,就得把观点变得明朗些。