"你一定要帮我！"

Translation: You must help me!

[MartinCarn4]

一定 means in general term " be sure ". But the correct answer was You HAVE to help me... "You Have to" in general term means 不得不。

[Zesul]

Would "你一定帮我！ " also be correct and mean the same?

[Bill496592]

You need 要 otherwise the sentence misses "command"/imperative tone.
https://www.chineseboost.com/grammar/five-uses-yao/

[josueetcom]

Interesting article! But it says "要 is pretty much only used to form negative commands." That being said, I'm not sure which form of 要 is being used here.

[MichaelLe3139]

Do we actually need 要 here, since "You must help me" & "You must WANT to help me" do mean differently to me.

[Bill496592]

要 in here is not for want. It is to form an imperative sentence. https://www.chineseboost.com/grammar/five-uses-yao/

[Handrisuselo]

What is "一定" here for? Does "一定要" mean "to have to; must"?

[BZH1423]

According to Duo, yes

[GD-TO]

This site is helpful to explain 'Commands' as part of the 5 uses for 要 https://www.chineseboost.com/grammar/five-uses-yao/

[CharlesEva1]

差不多， 可“必要”的意义有“must"或”need to"的感觉，“一定要”更有英语的“certainly will“。

[Jacques439990]

Yes

[samertabbal]

必要和一定要一样吗？

[Anonymous_Weeb]

我觉得它们一样。我觉得还是有一点的差距的。这是因为必要和一定两个都是在说：“你必须要” 做什么事情。我觉得它们想一个人不是在问如果你要不要做，他们一点儿像他们在逼你做还是他们很想你做，只是不是那么严格的那样子。这一点儿像如果你的老板想你做一个东西，只是在这情况下，你不是必要做。

[xialuote1]

You really must help me

[RonSawkaWa]

"Indeed you need to help me", is what I wrote. Yiding means "for certain", or "indeed", or "to be sure".....