They've got nobody to rely on.

They've got nobody to rely on.

他們沒有人可以依靠.
換做中文習慣說法---> 他們無依無靠.

句型: S+V+O+OC

to rely on是受詞補語(OC)
nobody是rely on的受詞.
rely是不及物動詞, 需與介系詞on或upon搭配, 才可以有受詞.

類似片語:
somebody to call on 某個要拜訪的人
nothing to worry about 沒啥要擔憂的事
any project to carry out 任何要實現的計畫
something to be proud of 某件引以為榮的事

如果to V這個V是及物動詞, 就不需要加介系詞了, 例如:
nobody to trust 無人可信任
nothing to eat 沒東西可吃
any porblem to solve 任何要解決的問題


2014-01-05 17:53:58 補充：
本句並不是非用現在完成式不可, 而是什麼時態都可以, 看你的時間背景而使用.
have got是指到現在為止的情況.
They never get anybody to rely on. (不變的事實)
They got nobody to rely on when they lost everything. (過去的狀況)
They were getting nobody to rely on when I saw them. (過去某時點的持續狀況)

2014-01-05 17:54:12 補充：
They will get nobody to rely on if they keep their mind closed. (未來條件)
They had got nobody to rely on before they met James. (到過去某時點為止的狀況)
......等等.

2014-01-05 17:57:29 補充：
>There is nobody to rely on.
這樣寫主詞是nobody, 單看這句看不出是誰無依無靠
但從前後文可以判知.

I've got = I have
這是習慣用法. 跟現在完成式沒什麼關係.
They've got nobody to rely on.
= They don't have anybody to rely on.

They've got nobody to rely on.
應該就是中文裡的：有......可以......
這句話是 他們沒有半個人可以依靠。

其他例句如：They finally got something to eat. 他們終於有東西可以吃了
I finally got a book to read. 我終於有書可以讀了
He finally got someone to talk to. 他終於有人可以跟他聊天了

希望對你有所幫助嚕

2014-01-05 10:50:45 補充：
用have got 主要是強調，有點像是中文說他們現在「已經」沒人可以依靠了。
如果沒有要強調，也可以只說 They got no one to rely on. 但是語氣就會減弱

至於為什麼要用got
我覺得是習慣用法，這樣用會比較道地。

至於你說的There is nobody to rely on. (沒有人可以依靠)
這樣就看不出主詞是誰，是我、是你，還是別人無依無靠
句子本身的文法可能沒有錯，但句意不清，聽起來也不那麼道地。

I have nothing to do.
與此句型一樣


have got=現在完成式