ugent,English grammar

正如你所說，在情態動後(modal verb)之後，我們即會用bare infinitive，如：
You should do it!
I can't imagine it.
但never只是副詞，而不是情態動詞，所以never不會影響之後所用的詞，而決定權，在於句子的助動詞，或其情態動詞等等。
如：
I have never heard it before.(因有助動詞have，所以用past participle　heard）
I will never go there again.（因有情態動詞will，所以用bare infinitive go)
希望幫到你！

You should use simple present tense because there is no specific known time. e.g. You should do this for me. You cannot do this for me. Don't do it!

Never means 從不or永不.

If it means 從不, it means you have not done this before, so you use past tense. e.g. You never heard of it before.

If it means 永不, it implies you will never do this in the future, so you use future tense. e.g. You will never do it again.

''should/shouldn't/can/can't/cannot'' and ''never'' 之後通常用不定式動詞(你講得岩, 就係infinitives 果d)
eg. you should do this/ you can do it!
OR
eg. you can have some of my chocolater./ you can't have them.
eg. you can never make it! 等等..