Нужно ли знать английский язык программисту. Ответить полностью и почему.

Actually, English is now so popular that you need to know it regardless of your profession. Thus, if you want to learn to be a good or excellent programmer, you need to learn a lot, and English is the best language to learn in. Also, if something goes wrong, you may want to search for it, so English is useful again.