别管……都, 任……也, 无论如何: no matter what, in any case
【高74】【高111】【高112】复句、固定短语 / complex sentences (条件)
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
别管 / 任 / 无论如何: three ways of saying "no matter what", from colloquial to formal.
别管 + question word or alternative，都…… is the colloquial, slightly imperative form of 不管 (HSK 4): "never mind…". It needs a question word (谁, 什么, 多晚) or an alternative (A 还是 B, 来不来), and the main clause carries 都: 别管台下坐的是谁，你都要充满信心。
任 + subject + 怎么 + verb，也 + negation means "however much he may…": the subject can go about it as he likes, the result does not change (任他们怎么推，也推不动). It is more written and more vivid than 别管.
无论如何 is a fixed adverb. Alone, at the head of a sentence, it means "in any case, whatever happens" (无论如何，他没有别的选择); with 也 it means "under no circumstances" before a negation (他无论如何也不答应) and "at all costs" before 要 (我无论如何也要去). Do not confuse it with 反正 (HSK 4), which is more casual and offhand ("anyway, I don't care").
Examples
别管多晚，我都会等你。
Bié guǎn duō wǎn, wǒ dōu huì děng nǐ.No matter how late it is, I'll wait for you.
别管台下坐的是谁，你都要充满信心。
Bié guǎn tái xià zuò de shì shéi, nǐ dōu yào chōngmǎn xìnxīn.No matter who is sitting in the audience, you must stay full of confidence.
任他怎么劝，她也不肯改变主意。
Rèn tā zěnme quàn, tā yě bù kěn gǎibiàn zhǔyi.However hard he tries to persuade her, she refuses to change her mind.
无论如何，他没有别的选择。
Wúlùn rúhé, tā méiyǒu bié de xuǎnzé.In any case, he had no other choice.
他无论如何也不答应。
Tā wúlùn rúhé yě bù dāying.He won't agree under any circumstances.
这次比赛我无论如何也要拿到名次。
Zhè cì bǐsài wǒ wúlùn rúhé yě yào nádào míngcì.In this competition I'm going to get a place at all costs.
Common mistakes
✗ 别管他来，我都去。 → ✓ 别管他来不来，我都去。 (别管 needs a question word or an alternative: A 还是 B, A 不 A).
✗ 他无论如何不答应。 → ✓ 他无论如何也不答应。 (无论如何 before a negation takes 也).
✗ 任你怎么劝，他不会改变主意。 → ✓ 任你怎么劝，他也不会改变主意。 (in its second clause, 任 goes with 也 or 都).