Kids like to play all the time, so the basic approach should be to indulge them in interactive games which make them learn while playing. Studies by their basic name is the biggest repellent for kids, so lure them with planned activities that your kid will learn to do.
I will discuss some of the Spoken English Exercises for Children, but it does not end here. There could be many exercises, you have to make your kid speak in English, and that too correctely.
Play English Rhymes with your childOne very important requirement is that you yourself get involved, that will create a high level of interest in the child for doing that exercise. There are plenty of English rhymes (I still remember the Twinkle Twinkle Little Star...) kids love to sing.
Grab your kids attention by singing the rhymes yourself, this will attract the child and he will try to sing along with you. Don't force him if he does not respond, it may take some time for him to start getting used to the exercise. Make sure he enjoys it.
Play English Scrabble with your child
Scrabble is game in which the child is supposed to make words from letters. Kids like to spread things, so just spread the English letters on the ground, and start making some words yourself. Keep pronouncing the words while making them. Slowly your kid will also want to join you.
Once he is in the game, ping him for each word he makes, like what's the meaning of this word, how do you pronounce it, etc. This will ensure a verbal session for your child, and keeps him involved.
Make him read the newspaper loudlyIf your kid is bit bigger, and able to read newspapers. Just show your child that you are very busy and have no time to read the newspaper, so could he read the newspaper loudly to you. This will improve his spoken English and also you can keep a tab on his pronunciation that it is correct or not.. That's why I stress so much on reading English newspapers loudly.
Keep a look on his areas of interestAlways keep your eyes and ears open to the areas your child is most interested in. This will help you devise more exercises and activities by yourself for you kids. The main aim is to make them learn spoken English while they are enjoying their playing session.