英文grammar問題~

They are swimming in the pool. (這句子沒有 object)

They 是 subject
Are 是 auxiliary verb (also known as helping verb)
Swimming 是 full verb (also known as main verb)
In the pool 是 adverbial phrase.

"are" + "swimming" forms the Present Continuous tense.

“swim” 在這句子是 intransitive verb, 所以沒有 object.
Intransitive verb doesn’t take an object.

To 回答者 Wilson_c:

pool 不是 object,不過在 adverbial phrase 內.

She swam the Channel.
(swam 是 transitive verb, Channel 是 object.)


Parent 是 father or mother of a person or animal. Parent is singular. 
“Parents” is plural, 是父母.(both father and mother). 所以不用加 –es.
Parents 可解多對父母

Boy is singular, Boy 加 –s 變成 plural form, Boys. 
Boys 不用再加 –s. Boys 已經是兩個或以上男孩

S = They
V = are swimming
O = pool

are = verb-to-be
swimming = verb ( in the form of present continuous tense)

It is needless to add "s" and "es" after "boys" because
"boys" is in plural form.

So does " the parents".

When you see a verb with a vowel at the end ( penultimate place) like "play",
you should add "s".

Vice versa.

For more details, please check the third column in the
following website:

http://www.uwants.com/viewthread.php?tid=9066833

2010-08-25 23:09:43 補充：
Strictly speaking, "swimming" should be a present participle.