"She needs to leave now."

Translation: 她现在必须要离开。

[Dr_Jerry]

I'm not sure I have ever seen 必须 used in conjunction with 要. Why is 她现在必须离开 not acceptable?

[looli23]

必须 and 必须要 are almost always interchangeable. You can interpret 必须要 as "must need", it's more like an accentuation to 必须 (must).

[Dr_Jerry]

Thanks for the explanation. I've been a Chinese speaker for over a decade and even studied the language formally at a Chinese university for two years (I'm simply doing Duo as a way of keeping my skills sharp now that I'm back in the US), and it just seems a little odd that I've never encountered 必须要 before.

[looli23]

wow~

Knowing that you know the language will make the explanation easier.

Think about this sentence: 人必须要有耐心，特别是要有信心。

Without 要 it would sound weird, so 要 is not always dispensable imo, and it's pretty natural here to use 必须要, however, I haven't studied grammar systematically (XD kind of sad to say that) to point out the grammatical reason behind. I think 要 appears because we say 要有，要做，要离开, so it's because it sticks to the verb and not much related to 必须. I would say the sentence is more 她|现在|必须|要离开 than 她|现在|必须要|离开.

Another example: 必须得想个办法。

If we want to add 要 in there, it won't be 必须要得想个办法, but rather 必须得要想个办法, so the 要 stays next to the verb. Adding a sense of emergency/must-be-done undertone to the verb.

[Dr_Jerry]

Interesting! Your explanation is very simple, clear, and insightful. Thanks so much for taking the time!

[looli23]

Glad to have helped :D

[jdebruycker]

This is now accepted 10/2019

[RobinThor]

What is wrong about 她现在要离开 and 她现在需要离开?

[maddisondawnfaye]

"她必须要现在离开" 不对吗

[KepaDuck1]

It's to do with the word order in Chinese; The time phrase (现在）must come after the subject and before the verb (必须）

Hope that helps!

[MaynardHogg]

Except when the time phrase precedes the subject.