Children don't learn language skills on their own, which makes it important for them to have play time at home with parents to learn and expand upon the early language skills they acquire. Even if your child is attending some kind of daycare program, that play/learning time at home is a terrific reinforcement for anything they're being exposed to formally. Here are some of the best ways to help develop your child's language skills, and to encourage usage of those skills once they've been learned.
Associate sounds with objects
One of the first play sessions you should promote with your children, at least when they're ready for language, are sessions that associate sounds with objects. For instance, you can make a train whistle sound while showing a picture of a train, or you can show a picture of a cow, and doing your best "Mooooooo" sound. By talking constantly with your child and making these sound/object connections, you'll be encouraging your child to repeat those same words.
What am I holding?
This game is for children who are a little older, and have at least a rudimentary grasp of language, because it involves the usage of descriptors when talking about specific objects. Here's how you play: put several small objects or toys in a box or other receptacle, so that your child can't see in. Then pull one object out without letting him/her see what it is. Then ask the child to guess what you're holding, based on the verbal clues that you provide. For instance, if you've pulled out a toy duck, you might just make a quacking sound. For a flower, you might say things like 'pretty, plant, smell, colorful, or garden'.
Where does it go?
A great way to have fun and have your child learn language skills at the same time involves the use of directional words. For instance, you could ask your child to put a toy on top of a chair, or along side the chair, under the chair, or even to hold the toy over the chair. This will convey concepts of positioning and direction, and you can make the game a little more interesting by providing a reward for a number of correct actions.
Adventures with heroes
For older kids, you can really drive home language skills by inventing your own stories which include action figures a boy might own, or possibly dolls that a girl might own. With each of you holding one of the figures, begin a story or an adventure as though you were the figure you're holding in your hand. After every statement you make to advance the story line, have your child respond with an appropriate line to advance things even more.
Playing with Wonder Gears
You might think that educational toys like Wonder Gears can only teach scientific-related skills, but if you're being thoughtful enough, you can expand that to include language skills as well. Take turns naming each part that you add on to your Ultimate Creation, and if you ever get through all the parts, start adding a different descriptor each time, e.g. 'red spiral', 'green gear', 'small gear', 'straight bar', etc.