Thread: When to use words of similar meanings?

Здравствуйте! If I may ask, I was wondering when is the appropriate times to use words of similar meanings such as: "сейчас" and "теперь" or "нужно" and "Надо"? Thanks.

"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!

To expand somewhat, I think надо is a bit more colloquial than Нужно. That is to say, you're more likely to read Нужно than надо in a text. But that's just a personal observation, you might want a native speaker to confirm/deny that for you.