"Please write with a pencil."
Translation:Пожалуйста, пишите карандашом.
English phrases "to write with a pen", "to decorate with chocolate", "to repair with a screwdriver", etc. are often translated into Russian using the instrumental case. Essentially, the function of the preposition "with" in these cases is to deliver the same meaning as "by means of", "by the use of". That's what the instrumental case does in Russian, so "with" doesn't appear in the translation as a preposition.
"To write with a pen" = Писать ручкой
"To decorate with chocolate" = Украшать шоколадом
"To repair with a screwdriver" = Чинить/ремонтировать отверткой
There are seemingly identical cases where you will have to carry "with" into Russian translations:
"To play with children" = Играть с детьми
"To sigh with relief" = Вздохнуть с облегчением
We still use the instrumental case in the translations. However, in these cases "with" doesn't have the meaning of "by the use of", so we need the preposition; otherwise, the original meaning will be lost.
I hope this helps.
I believe this word order is correct. At least it sounds absolutely natural to me. Please report it.
Although I knew the "correct" answer used пишите, I tried напишите, but got marked wrong. Is it? I recall notes saying that a perfective is preferred for a positive imperative, but perhaps because this focuses on the process, imperfective is better? Native speaker?
I agree, both пишите and напишите should be accepted here. They do bear slightly different meanings, at least the way I hear it as a native speaker. Пишите sounds like a generic request: "In general, please write with a pencil". Напишите sounds more like "Please write [this particular thing] with a pencil".