How to say "would have" sentences

[Jose]

I was wondering what would be the best way to translate into Chinese hypothetical sentences like the following ones:

If you had told me, I would have helped you.

If you had studied harder, you would have passed the exam.

I think I would probably use 了 in the "if" part, and 早就 in the second part, but I am not sure if that would be correct.

[tanhql]

If you had told me, I would have helped you.

(如果/要是)你早告诉我的话，我(是)会帮你的。

If you had studied harder, you would have passed the exam.

(如果/要是)你有用功读书的话，你的考试(是)会及格的。

it still sounds a bit strange though.

[Long Zhiren]

The trick in Chinese is that there is no subjunctive, past perfect or future perfect verb tenses. In fact, there really is nothing but present tense.

You'd need to convey the same thought using context and other devices.

[andrewfz]

I believe its....

如果你告诉我了，我可以帮助你。

As far as I can see there is no conditional tense verb alteration...just the addition of a conditional phrase like 如果 or 要是

[Jose]

Thanks for the answers.

I have continued to think about this point. I am perfectly aware that there is no verb tense in Chinese and that, as Long Zhiren, said, these thoughts can be conveyed using context "and other devices", but it is precisely those other devices what I was trying to identify.

Tanhql's answer is especially interesting because it shows something that I have often noticed, and which textbooks seldom mention, which is that "would" sentences are often rendered by using 會 in Chinese.

After talking to some Chinese friends and getting different answers from them, it seems to me that the best way to express this type of hypothetical sentence combines two features:

Firstly, in the condition part, we usually need some time adverbial to somehow push back the time frame to the past. This is often done by using words like 當初 or 那時. I am not completely sure about this, but I also think that adding 的話 to the sentence makes it sound more hypothetical.

Secondly, the latter part of the sentence (I would have...) is usually rendered by using 會 or 不會, often preceded by 就.

To know whether these rules of thumb work, I will offer my attempt at translation of the two sentences I mentioned. I would appreciate it if anyone could tell me whether they are acceptable or whether they sound awkward or plainly wrong.

If you had told me, I would have helped you.

如果你當初告訴我的話，我就會幫助你。

If you had studied harder, you would have passed the exam.

如果你當初更努力地學習的話，你就會通過那次考試。

Let me try to do two more examples, and see if this works.

If I had known that she had a boyfriend, I wouldn't have told her I was in love with her.

如果我當初知道她有男朋友的話，我就不會告訴她我愛上她。

If I had known that she didn't have a boyfriend, I would have told her that I was in love with her!

如果我當初知道她沒有男朋友的話，我就會告訴她我愛上她！

In the above sentences I have consistently used 當初 to set the time frame in the past. I think 那時 would be valid too. I have asked some Chinese friends about the possibility of using 原來 and 本來, and while the first seems to be acceptable, they thought 本來 sounded awkward. A google search ("如果我當初知道" v. "如果我本來知道") seems to confirm this point, although I am not sure if I understand why 本來 cannot be used in these sentences.

Just some more food for thought. As always, feel free to point out mistakes, missing 了s and whatever.

[LaoLiang]

How's this one:

早告诉我就帮你啦！

[Jose]

Thanks, LaoLiang! That's very helpful. Your sentence is certainly much more idiomatic than my poor attempts at a literal translation.

Thanks to your example and the first one provided by tanhql, I can now see how 早 is also very commonly used for this kind of sentence. A Google search also confirms this (如果我早知道的话 and 如果你早告诉我). The search results provide some very good examples of this kind of counterfactual sentence.

I think I am finally starting to recognise a clear pattern for the "if I had known" type of sentence, something like:

(If-word) (+ subject) + 早 / 当初 / 那时 + verb (+ 的话)

Interesting, thanks a lot for the help.

[YETIboy1230]

早告诉我就帮你啦！

It is somewhat weird to me.I hardly speak that way.Instead,i wound be more likely to say“早说(的话)，我就帮你啦！”.Anyhow,maybe that is my own cup of tea

And further more,if I intend to use "當初“，I personally prefer to combine“要是”with it.e.g,要是我當初知道她沒有男朋友的話，我(早)就告訴她我愛上她了。