If a person says wrong, then his opinion most people is not serious. Moreover, such a speech can be very annoying. A man, whose beautiful and correct speech, is a great conversationalist.
In order to learn how to clearly Express their thoughts in the first place, you need to read a lot. Although in this age of computerization and the Internet on books almost no time left, reading still remains an important source of literacy and language. When a person reads, he learns to construct sentences, enriches your vocabulary, improves spelling. It is very important that the reading was not a burden, but fun. First of all, it concerns the children: teach children to read, but in any case, do not force to sit for hours on a book.
Record your speech on a disk and listen to yourself. This way you will be able to hear their speech errors, word-parasites, wrong accent. When you know your mistakes, and deal with them easier.
Enrich your vocabulary. If you meet a new word, try to figure out its origin and meaning. But don't overuse such words, because their abundance infests it.
Always keep a dictionary on hand. With the help of a dictionary, you can always check the meaning of unknown words, find antonyms and synonyms to various words, properly arrange the accents.
Check the texts that they write, be it essay or a simple message. Check whether you formulated the idea, whether the meaning is clear to others.
To improve their skills and using the different games. It could be crosswords, charades, and rebuses, and developing intellectual game. With the help of such simple means it is possible to develop the ability to speak correctly, nice and clear.