Speak English and be better understood by using sentence stress correctly. When you highlight or exaggerate a key word in a spoken sentence, you can really change the understanding for the listener. Listen to a native-speaker English teacher from the UK pronouncing the same sentence in different ways and changing the meaning just through pronunciation/intonation.
SGI is an English School in Central London with Pronunciation courses... as well as a range of other English courses.
http://www.stgeorges.co.uk/english-courses/english-pronunciation-course
http://www.stgeorges.co.uk/