我愿谈谈一个比较浅显然而又很有趣的问题，即英语中词类相互转化的现象。
让我们先从名词谈起吧。名词可以转化为动词，如我们比较熟悉的 book （登记册）、fan （扇子）等，如：
(1)We've booked seats for tomorrow's football match. （book 在此意谓“预订”）
(2)She fanned herself with the newspaper to cool her face. （fan 在此意谓“扇”）
但你知道像 pressure （压力）和 position （位置）这样的名词也可以转化为动词吗？请看：
(3)Sadat's strategy is to let the US pressure Israel if possible, into making concessions. （pressure 在此意谓“向……施加压力”）
(4)He positioned himself just by the window so he could see what was going on outside. （position 在此意谓“将……放在适当的位置”）
更为有趣的是 brother （兄弟）和 sir （先生，老爷）也可转化为动词，如：
(5)Don't brother me. （brother 在此意谓“称兄道弟”）
(6)You mustn't sir me. （sir 在此意谓“称呼 sir”）
名词也可转化为形容词，如 fun （玩笑），light （光）等，如：
(7)She's a fun person to be with.
（fun 在此意谓“好玩的”或“有趣的”）
(8)The moonlit night is as light as day. （light 在此意谓“光亮的”）
名词也可以转化为副词，如表示时间的名词 Sundays, mornings 等，尤其在美国英语中皆可转化为副词，如：
(9)They go to church Sundays . （Sundays = on Sundays）
(10)She works mornings . （mornings = in the morning）
现在再看代词是否也可以转化为别的词类。答案是肯定的，例如常见的 something, nothing 等不定代词即可转化为名词，如：
(11)As they came up, he made out that they were gathered round a something that was carried on men's shoulders. （注意这里的 something 之前有不定冠词 a，故已转化为名词）
(12)He spent the whole evening whispering sweet nothings in her ear. （这里的 nothings 是复数形式，故已转化为名词）
其实代词之可以转化为名词并不限于不定代词，人称代词亦可转化为名词，如：
(13)What is the use of being friends with the angry you ? I would much rather be friends with the happy you . （这里的两个 you 都有定冠词 the，故已转化为名词）
(14)This me you look at is my whited sepulchre. （这里的 me 之前有 this，故已转化为名词）
形容词转化为名词的情况就更多了，这种情况在语法上唤作“名词化的形容词”，例如：
(15)The beautiful can never die.
(16)I shall do my possible .
(17)Don't be a silly .
(18)This old man suffers from the blues .
(19)She kept all her valuables in the bank.
形容词转化为动词的情况也不少，例如：
(20)He was starting to shake with excitement, and to calm himself he walked over to the window.
(21)The clothes dried quickly outside.
(22)Don't dirty your hands.
(23)They emptied the rubbish into plastic bags.
(24)Harold slowed the car down.
形容词转化为副词的情况也不罕见。中国学生对此情况应该多加注意，故愿多举一些例子如下：
(25)I'm awful sorry. （形容词 awful 转化为副词）
(26)I'd clean forgotten to turn the light off.
(27)The boy ran clear through the house without stopping.
(28)Do you like this shirt? I bought it real cheap .
(29)Come close ; I want to tell you something.
(30)He stopped cold when he heard a noise behind him.
(31)They expected us to be angry, but we had decided to play it cool .
(32)We were dead tired.
(33)Her decision to marry him cost her dear .
(34)He went deep into the wood.
(35)The train goes there direct .
(36)Take it easy .
(37)We must play fair .
(38)You're doing fine .
(39)Spread the map flat on the floor.
(40)Babies are allowed to travel free on buses.
(41)The eagle soared high into the sky.
(42)She often comes late .
(43)Don't speak so loud .
(44)The plane flew low over the field.
(45)The weather is mighty fine today.
(46)Bob lives near .
(47)That's just plain stupid!
(48)Tell us quick .
(49)You can buy the bread ready cut.
(50)It's real cold today.
(51)All went right .
(52)I could scarce believe my eyes.
(53)The wind whistled sharp under the closed door.
(54)His salary was cut short by his master.
(55)Drive slow down that hill.
(56)Cool it. Get your hands off me. Talk softer and slower .
(57)Chris is still sound asleep.
(58)Clarence is sure lazy. （在美国英语中形容词 sure 转化为副词）
(59)She held on tight .
(60)He opened the door wide .
(61)What did I do wrong ?
关于形容词转化为副词的现象，有几点值得注意：1.这种副词还有很多，如 decent, dreadful, exceeding, fierce 等。它们多为非正式英语，有的尚未被一些词典纳入。2.有些副词已从其源自的形容词有所引申，意义有所不同，如 clean, cold, dead, mighty, plain 等。3.这种副词一般都可加上词尾-ly 变成另一种副词形式。这两种形式之间往往有程度不同的差别，需要特别注意。
由于篇幅的限制，其它词类转化现象我们只能简要地举几例如下：动词转化为名词：
(62)The child had a bad fall and hurt himself.
(63)We had a good laugh at his joke.
(64)We decided to go for a swim .
注意情态动词 must 也可转化为名词，如：
(65)It's an absolute must . （must 作“必不可少的事物”解）
副词转化为名词：
(66)Now is the time to tell him the truth.
副词转化为形容词：
(67)The matter was reported to the then Prime Minister.
副词转化为动词：
(68)The crisis in Northern Ireland neared a flash point last week.
副词 near 等，还可以转化为介词，如：
(69)Her father was angry, her mother near tears.
介词可转化为名词，如：
(70)Bill explained all the ins and outs of the case to me. （ins and outs 作“细节”解）
介词可转化为副词，如：
(71)Come in , please.
连词可转化为名词，如：
(72)I'm tired of your ifs . （if 作“假设、条件”解）
连词可转化为动词，如：
(73)But me no buts.
数词可转化为名词，如：
(74)He quickly ate everything on his plate and asked for seconds .
最后，饶有趣味的是有些感叹词也可以转化为其他词类，如：
(75)The hurrahs of the crowd filled the air.（hurrahs转化为名词）
(76)He hemmed and hawed around and finally said what was on his mind.（hem和haw转化为动词）
词类转化是英语构词法的一种。它是生命力很强的构词手段。它不仅可以丰富语汇，而且可以使语言显得更加准确、鲜明、生动。学习英语的人通过词类转化可以扩大词汇量，提高英语水平，所以应该随时予以注意。
