It depends what you mean by phrases. If you use a lot of idioms or jargon, it isn't necessarily a good thing or an effective thing. they are plenty of sites offering the secret keywords or phrases for effective sales, etc, but generally their claims are dubious or false.
If effective communication simply depended on including a number of phrases for every situation, then everybody would know it and do it. A lot depends on all sorts of other things like tone of voice, manner, etc.
What you said is correct but i have a set of Friend's who use a lot of idioms ,phrases while speaking language it sound really impressive .Also i cant be always asking them the meaning i may appear a idiot in fornt of them.. hence i have poseted in so that if there are few sources i may follow them or read as much to improve the spoken language..