Thread: When to use words of similar meanings?

"сейчас" and "теперь" are often interchangeable.
Actually it has been asked many times on this forum.

Extract:

Теперь more often means "nowadays", "at present" while сейчас more often means "right now".

Also теперь is often implies the idea of consequence while сейчас do not. Теперь often can be translated as "after all", "from that time", "from now on".
- Вчера споткнулся, выходя из туалета. Теперь знаю, что значит выражение "убиться об стену".

Нужно and надо are also mostly interchangeable but often "мне нужно" means "I need" while "мне надо" means "I have to".

Огромное спасибо!