Any person who is engaged in-depth study of the language thinks about how to increase the vocabulary of this language. Being it his native language, or a foreign language, the increase of vocabulary is paramount for success. If talking about English language, one of the major basic problems in the study English is to increase the number of actively used words, which increases the level of human literacy and make a significant diversity in his speech. To qualitatively learn new words, you need to spend a lot of time and exert the maximum efforts.
There exist a few simple and fun exercises using and following which you can expand your English vocabulary. Read more books and try to learn the meaning of new words from context, use linguistic intuition, which in turn will allow you to eventually develop a sense of the English language. Memorizing words in context and not in the dictionary will help you faster to remember not only the meaning of the word, but also the rules of its use. During the reading focus on how using prefixes and suffixes are formed new words from the already familiar to you. This will help you to feel the language. With this simple method while reading you will learn word-formation, you will understand the principles of construction of new words and subsequently encountering an unfamiliar word, you will be able to guess its meaning without a dictionary, based on the context and your experience.
Choose to read a text in which are included unfamiliar words. Write them down and try to break into meaningful groups. Try to draw a mind map and then retell the text, relying on this mind map. Interrelated concepts are remembered easier than fragmented set of words. And while drawing the map you have to write words including in the process of memorizing the mechanical memory. You can supplement your mind map or a regular dictionary with synonyms. Find synonyms for new words and write them nearby, at the same time among them should be at least 1-2 words familiar to you, then to remember new vocabulary will be much easier. You might also write antonyms, as for some people it is more convenient to learn groups of words. To find proper synonyms and antonyms for words you can use Power Thesaurus online dictionary. This is the best thesaurus dictionary which contains 444K of words, 19 million synonyms and 2.3 million antonyms. Using all mentioned above recommendations you will considerably increase your vocabulary and will be able to develop your conversational language.