Vocabulary is the most demand knowledge/skill that one should have but its not easy there are 1000 of words in English language.It is difficult to remember the meaning of words and when it comes to exams like cat,AM cat,co cubes ,jobs/placement everybody wants you to have good vocabulary,but the question is how to get that rich vocabulary.There are few things you can do in order to achieve that.
Focus on the root word there are a lot of word which can help you to figure out the meaning of another words.For eg- arium/ary refers to a place so words like aquarium -we all know the meaning of aqua that is water and arium means place so we can guess that it means a place where fish lives, library- place where books are kept. Another example could be Eu- good and the word euphoria means sense of goodness.so sometimes focus on the root words there meaning is somewhat similar.
Focus on suffixes and prefix there are a lot of prefixes and suffixes whose meaning you know and when they are added in particular words there meaning changes slightly not completely but slightly.For eg mis- bad/wrong here have a look mistake- error, misfit-not a suitable person
Try to read books and note down the word if you don’t know the meaning of the word, and if you don’t have time for reading books try randomly selecting the words from google revise them daily and slowly try to use them while writing and speaking hence improving your vocabulary.
Learning and revising is the key if you find a new word but don’t know it’s meaning try to find out the meaning of that particular word and try remembering it and using it in your very own way.English is an interesting language you just need to understand it, work on the mention above points you will find yourself improving.