From a lesson in a Chinese text book was the following sentence:
他不由得哭 (Tā bùyóude kū)
He could not help but cry
I've never heard 不由得 used in a sentence, and I want to know if it is common and if not, what is typically used.
The sentence I was hoping to say is:
"I can't help but blame you"
Google translate offers the following:
我不禁责怪你
In particular I want spoken Chinese rather than written if there is a difference.
There are actually two meanings of "can't help but" here, with a rather subtle distinction. In your first example, the guy cannot control the fact that he wants to cry - he simply let go of his emotions. In your second example, you can control your behavior, and in fact you're very determined to do it.
In the first example, an equivalent phrase would be:
不由自主地 (did something without control)
In the second example, an equivalent phrase would be
没有办法不[责怪你] (have no choice but to [blame you]).
You're right that the phrase 不由得 is rarely used. In fact, when it is used, it usually has a different meaning: telling another person "You have no choice", e.g.
这件事情不由得你 = You have no say in this matter
First, both of your examples are a little awkward. The following changes make them more natural Chinese sentences:
他不由得哭了。
我不禁要责怪你。
Second, yes, both 不由得 and 不禁 are more common in written instead of spoken Chinese. A colloquial expression will be 忍不住:
他忍不住哭了。
我忍不住要责怪你。
... can't help but ... implies I don't want to do so but I can't control my feelings. So does 忍不住.
For your first example, you can also use 不由自主地. It has the same meaning, but is more of written style.
他不由自主地哭了。
As for other suggestions such as 不得不 and 没法不, the meaning is a little different. It means I don't want to but the objective circumstances compels me to do so. It is more a description of the physical world than an expression of the psychological mood.
他不得不哭。(In this case, there is no 了 at the end of the sentence. He had to cry but we do not know if he actually cried. The same below.)
他没法不哭。
我不得不责怪你。
我没法不责怪你。
I can't help but
在你的两个例子中, 忍不住是最好的选择. 表达了人物想控制, 但是控制不住自己的情绪.
In your example, 忍不住 is the best fit choice. It express the person that want to control himself but failed.
The best direct translation to the phrase ... can't help but... that I can think of is ...不得不...
He can't help but cry - 他不得不哭
I can't help but to blame you - 我不得不责怪你
I can't help but to think of you - 我不得不想你
The phrase ...不得不... basically means one might not want to do something, but is compelled by whatever reason to it anyway. Which is very similar to the meaning of the English phrase ... can't help but....
