Your 5+ year old child is fairly aware about themes and concepts. Give them themes and concepts and in no time they will build a whole world around you. So, teaching them anything based on themes is an interesting and fun way to go about it.
What you need to know
Since we know that to enhance a child’s language skill, it is important to build vocabulary, doing it in a fun way is always fruitful. Introduce your child to themes and ask them all the words they can think of. For example, let the theme be 'HOUSE'. Ask your child to tell all the words that are associated with house. You child is likely to come up with common words like door, window, bedroom, bathroom and many more. Don't leave it where he stops. Now give him words that he missed and help him associate those words with the theme. This way it will be easy for him to memorize these words.
Building words in these fun ways interest kids, and they don't feel that they are being taught something consciously. Rather it turns out to be a fun game that they will like to play time and again during the day or week. Theme based learning is thus a very productive and interesting way to increase the vocabulary of kids. Not only does it help kids learn something new, it is also a beautiful way to bond. If you haven't, try it now and watch out for the difference it makes!