这些动词均含有“变化，改变”之意。
change : 指任何变化，完全改变，强调与原先的情况有明显的不同。
- Rick hasn't changed. He looks exactly the same as he did at school.
里克一点儿没变，他和上学时一模一样。 - changing attitudes towards education
不断变化的对教育的看法 - Her life changed completely when she won the lottery.
买彩票中奖后她的生活完全变了。
alter : 常指轻微的改变，强调基本上保持原物、原状的情况下所进行的部分改变。
- Prices did not alter significantly during 2004.
2004年期间，价格没有大的变化。 - He had altered so much I scarcely recognized him.
他变得我几乎认不出来了。 - It doesn't alter the way I feel.
这并没有改变我的感受。 - Nothing can alter the fact that we are to blame.
错在我们，这是无法改变的事实。 - The landscape has been radically altered, severely damaging wildlife.
地貌彻底改变，严重损害了野生动物。
vary : 暗示不规则或断断续续地变。
- The job enables me to vary the hours I work.
这项工作使我能够调整工作时间。
convert : 指进行全部或局部改变以适应新的功能或用途。指信仰或态度时，强调较激烈、大的改变。
- Could we convert the small bedroom into a second bathroom?
我们能把这间小卧室改建成第二间浴室吗？ - What's the formula for converting pounds into kilograms?
把磅换算成公斤的公式是什么？
modify : 强调起限定作用的变化或变更。指细小的变化，常含“缓和、降调”的意味。
- Instead of simply punishing them, the system encourages offenders to modify their behaviour.
这个制度并不是单单惩罚犯罪者，而是鼓励他们改正自己的行为。 - The proposals were unpopular and were only accepted in a modified form.
这些建议不受欢迎，修改之后才得以接受。
transform : 指人或物在形状、外观、形式、性质等方面发生的彻底变化，失去原状成为全新的东西。
- The reorganization will transform the entertainment industry.
这次重组将使娱乐业大为改观。 - the power of art to transform experience
彻底改变体验的艺术力量 - Whenever a camera was pointed at her, Marilyn would instantly transform herself into a radiant star.
每当摄像机对准她的时候，玛丽莲会立刻将自己变成一个耀眼的明星。
turn : 指外形、颜色、气味、性质等方面的变化，比change更通俗。
- The weather has suddenly turned cold.
天气突然变凉了。 - When I refused to pay, he turned nasty.
当我拒绝付钱时，他的态度变得很恶劣。 - She turned pale and started to shiver.
她的脸色变得苍白，身子开始颤抖。 - The mood of the meeting turned solemn when the extent of the problem became known.
当问题的严重程度披露后，会议的气氛开始变得严肃起来。 - The companies worked well together for a while, but eventually the relationship turned sour (= became bad).
这些公司一度合作得很好，但最后关系闹僵了。 - Keele, pop star turned business tycoon, has launched a new range of cosmetics.
基尔，从流行音乐歌星摇身成为商业巨子，已经推出了一个新系列的化妆品。 - The dry weather turned the soil into/to concrete.
干旱天气使土壤板结。 - By the end of September, the leaves have started to turn (= become brown).
到9月底，叶子就开始变黄。 - Her attitude turned from politely interested to enthusiastic during the course of our conversation.
在我们谈话期间她的态度发生了转变，先是出于礼貌表示感兴趣，后来就变得很热情。
