點解go不用加s呢?

只有在 present simple tense 中, 主語 (subject) 是第三者單數 (third person singular) main verb 才會加 + s
(He,She, It, The boy,... ) + verb加 s (go 加 + es)

She goes to a cake shop

如果有助動詞 (auxiliary verb) 在 main verb 前面, main verb 不用加 + s
助動詞 (auxiliary verb) 包括有 can, could, may, might, shall, should, will, would, must
She can go.to a cake shop.
She may go.to a cake shop.
She must go.to the cake shop.

Does she go to a cake shop?
She does not go to a cake shop.
She does go to the cake shop. (單獨 does 在 main verb 前面, 是加強語氣)

在 "to" (infinitive marker)後面的動詞, 不用加 + s
She wants to go to the cake shop.

題外:
還有 had better = 最好, 必需, better 是作 adverb
She had better go to the cake shop. (不是 has better)

非常特別, 用 base form of the verb, 不是用 gone (past participle)
並且是 present tense, 雖然有 had 字, 不是 past tense



2013-11-01 10:38:43 補充：
She wants to go to the cake shop.
want 是主要動詞, 要加s
因為 She 是第三者單數, 並且用Present simple tense

其他例子:
He needs a pen to write. (needs 是主要動詞)
The girl decides to go home. (decides 是主要動詞)
He 和 The girl 是第三者單數

2013-11-01 10:51:37 補充：
I decide to go home. (I 是第一者單數)
We decide to go home. (We 是第一者複數)
You decide to go home. (You 是第二者單數)
They decide to go home. (They 是第三者複數)

只有主語是第三者單數,並且用 Present simple tense, 主要動詞 才加 s

There is absolutely no need to add "s" for the verb "go" in this sentence. The reason is because you use "can" before the verb.

She can go to the cake shop.

But if you say she is actually going there like the following:
She goes to the cake shop.
Then a "s" is needed.

因為can在go前面

記住 can 之後要用本字，不作變化～ ^__^

因為 go 和 can 連用。go 只單獨在 simple present tense 中才會加 es。