The most effective way to expand your vocabulary is to say a new word out loud to commit it to memory when you encounter it. carry a dictionary with you so you can look up unfamiliar words. write down new words and their meanings so you can look them up when you need them. use the words you've learned regularly when you write and speak.

use the words you've learned regularly when you write and speak.

Explanation:

Vocabulary is simply the word stock that a person uses frequently.

There are many effective ways of expanding one's vocabulary which are writing down new words and looking up their meanings, reading new material, etc but the most effective way to expand vocabulary is to use the words you've learned regularly when you write and speak because this is the surest way to make sure that those words you learned become your core languages.

not concrete, existing in thought or as an idea but not having a physical or concrete existence

answer: i am not sure but i think you should go for c

explanation: