英语的实词不但多义，而且同一词还可以属一种以上的词类。此外，从一种词类又可以转化为另一种词类，其中以⒈名词转化为动词、⒉动词转化为名词以及⒊形容词转化为动词，这三种最为普遍、最为生动。转化后的词具有该词基本的特性，因此转化名词有如真正名词，转化动词就像真正动词。

⒈名词→动词

① The workers found Bob's attitude hard to stomach.

② The parachutist had to nerve himself for the jump from his helicopter.

③ A few poor children had been dogging the tourists for some time.

④ Tuition schools have mushroomed for the last two years.

⑤ The traitor was knifed and stoned to death.

⑥ I leafed through a few pages of the book to see what it was about.

⑦ Personality clashes surfaced among some rival leaders.

⑧ Tom elbowed his way through the crowd.

⑨ It is impolite to ape one's superiors.

⑩ Delicious food made our mouths water.

⒉动词→名词

① The innocent girl was having a good cry.

② Active people are always on the go.

③ I often have a quiet read before going to bed.

④ People from all walks of life condemned a bad government.

⑤ Famine came in the wake of the drought.

⑥ The manager gave some lazy workers the sack.

⑦ Let me take a good look at these photos.

⑧ A visit to the Jurong Bird Park is a must for any tourist.

⑨ War is loathed by the haves and the have-nots.

⑩ If you have anything to discuss with me, don't hesitate to give me a ring.

⒊形容词→动词

① Don't idle away your precious time.

② Father's hair begins to grey.

③ How to quiet a fretful child?

④ We have no intention of seeing an innocent person humbled.

⑤ Something must be done to better the life of the underprivileged.

⑥ Language skills can be perfected by constant practice and regular reinforcement.

⑦ The robber wanted his victim to empty his pockets.

⑧ When the enemy's ships neared the land, our soldiers began to attack.

⑨ The man's muscles tensed as he saw the snake approaching him.

⑩ The hot weather soured the fresh milk.

此外，有些形容词和其他词类也可以转化为名词。例如：

① The strong tend to bully the weak.

② Poor innocents deserve our greatest sympathy.

③Richard looked like a silly in such a situation.

④ The secretary knows the ins and outs of the matter.

⑤ Do you know the whys and wherefores of the accident?

⑥ Though a rich man now, Peter's earlier life was marked by ups and downs.

上述这些转化名词，并未具有名词全部的特性。例如“the strong”和“the weak”形式是单数，意思是复数。还有④-⑥这些转化名词既有复数之形，也具复数之意。