The English language contains about 490,000 words plus about 300,000 technical words. It is doubtful if any individual uses more than 60,000 words. Written English uses about 10,000 words while spoken English, by the better educated, uses about 5,000 words.
Effective communication in the English language requires that we follow a few simple rules that can be learnt and practiced by anyone. We just need to keep in mind the purpose of communication.