Breakdown of Надень сапоги и смотри, не промочи ноги до водопада.
и
and
не
not
смотреть
to watch / to look at / make sure (in a warning)
сапог
boot
Questions & Answers about Надень сапоги и смотри, не промочи ноги до водопада.
Why is не промочи in the perfective aspect here? I thought negative commands almost always used the imperfective aspect.
You are right that negative imperatives usually take the imperfective aspect to tell someone not to do something. However, when you are warning someone against an accidental or undesirable action, you use не plus the perfective imperative. Не промочи means 'make sure you don't accidentally get them wet,' whereas the imperfective не мочи would mean 'do not actively or intentionally wet them.'
What is the purpose of смотри before the negative command?
Here, the imperative смотри (literally 'look') acts as a warning particle, similar to 'watch out' or 'see to it' in English. It is very frequently paired with не plus a perfective imperative to emphasize that you are warning the person to prevent an accident, rather than just forbidding an action.
I always mix up надеть and одеть. Why is надень used here for 'put on boots'?
The general rule is that you use надеть (to put on) for inanimate clothing and accessories, and одеть (to dress) for living people or animals. Since boots (сапоги) are items of clothing you put on your own body, надень is the correct choice. A helpful Russian rhyme to remember this is: Одеть Надежду, надеть одежду (Dress Nadezhda, put on clothes).
The translation says 'before the waterfall', but doesn't до usually mean 'until'?