Hello, Reale,
Yes, they are similar, but a native speaker knows exactly which one to use in any situation.
For something mandatory, we (in the US, at least) tend to use "have to" rather than "must", except in very formal writing.
If I say, "I must stop smoking", I am probably speaking to myself, sort of as a reminder or as a motivation.
If I say, "I have to stop smoking", I am probably telling someone that the doctor has ordered it.
You are right that "need to" is often used at the time of speaking, much as my "must" example above, as a reminder or a motivation. That isn �t always the case, though.
If I say, "I need to stop smoking", it isn �t necessarily a decision at the time of speaking. It is rather a general statement of something I am acknowledging as a necessity.
As a "time of speaking" example, there �s "I need to brush my teeth". This indicates that I just realized it, and it needs to be done now.
If I just ended a major coughing fit, then "I need to stop smoking" would be a "time of speaking" example, too.
Ah, what a wonderful language English is for exploring. I �m glad I �m a native speaker, so I don �t have to learn it! I really enjoy these opportunities to explain some of the finer points, because I have to stop and analyze the question before I can even consider giving an answer. Sometimes I don �t answer a question here because I don �t have time to do the exploring I need for a "Bruce answer".
Bruce
