general

[good samaritan]

should i ve known all the words in the dictionary to be good communicator?
and could you help me by giving some few vocabularies to communicate well?
and people in the forein countries 've known all the words to speak well english?

[RonBee]

You can't learn all the words in the dictionary. And even if you could memorize all the words in the dictionary that wouldn't mean you know how to use them effectively.

~R

[Harry Smith]

Welcome to the forum! If you want to speak English well you should learn the grammar in order to use the words you know. You need to know about 5000 words and combinations to speak English well.Cheers!

[RonBee]

Yes, 5000 words is about right, I guess. (But you can get by with fewer.) The important thing is to know how to use those words in sentences.

~R