Expressing an Imperative Without Knowing the Imperative

Question

Is there an alternative way to order someone if you don't know how to form the imperative out of a certain word? For example, I might want to say, "Don't smoke!" but I can't come up with "Не кури!"

Answer 1

You could say Не курить!. It sounds more like an order than Не кури!.
Another example: Don't make noise! => Не шуметь! instead of Не шуми!

Answer 2

Colloquially either Здесь не курят or Здесь курить нельзя.

If we talk about formal (written) prohibition then "Курение запрещено" or "Курить запрещено".

As generic construction, one may also use не нужно + any infinitive to avoid the imperative at all.

Answer 3

There's a lot of possible expressions without imperative, unfortunately those are also unlikely to help in that particular case.

Не надо здесь курить! 

Не могли бы вы в сторонке покурить?

Здесь нельзя курить. По новому закону - 15 метров от остановки.

Может, перестанешь курить (при детях)?