How to Speak Correct English

I. Observe the mouth movements of those who speak English well and try to imitate them.
When you are watching television, observe the mouth movements of the speakers. Repeat what they are saying, while imitating the intonation and rhythm of their speech.
ii. Until you learn the correct intonation and rhythm of English, slow your speech down.
If you speak too quickly, and with the wrong intonation and rhythm, native speakers will have a hard time understanding you. Don't worry about your listener getting impatient with your slow speech -- it is more important that everything you say be understood.
iii. Listen to the 'music' of English.
Do not use the 'music' of your native language when you speak English. Each language has its own way of 'singing'.
iv. Use the dictionary.

Try and familiarize yourself with the phonetic symbols of your dictionary. Look up the correct pronunciation of words that are hard for you to say.
v. Make a list of frequently used words that you find difficult to pronounce and ask someone who speaks the language well to pronounce them for you. Record these words listen to them and practice saying them. Listen and read at the same time.
vi. Buy books on tape.
Record yourself reading some sections of the book. Compare the sound of your English with that of the person reading the book on the tape.
vii. Pronounce the ending of each word.
Pay special attention to 'S' and 'ED' endings. This will help you strengthen the mouth muscles that you use when you speak English.
viii. Read aloud in English for 15-20 minutes every day.
Research has shown it takes about three months of daily practice to develop strong mouth muscles for speaking a new language.
ix. Record your own voice and listen for pronunciation mistakes.
Many people hate to hear the sound of their voice and avoid listening to themselves speak. However, this is a very important exercise because doing it will help you become conscious of the mistakes you are making.
x. Be patient.
You can change the way you speak but it won't happen overnight. People often expect instant results and give up too soon. You can change the way you sound if you are willing to put some effort into it.