At the age of 2, a child's vocabulary may consist of 200 words. By the age of 6 that child will have acquired 10,000 words. In order to accomplish this, children will learn up to 5 new words a day. Children connect words with their meaning after a short time of exposure. This is called fast mapping. Verbs are acquired especially fast in order to understand the relationship between and object and it's action. Children may create their own words in place of words that they may have not learned yet. For example, a child may call a gardener "plant-man". By contrasting words they already know, preschoolers are able to understand the meanings of new words. The first several hundred nouns learned will be organized by shape. This is known as shape bias. It has been found that preschoolers are most successful at learning new words when several kinds of information are available. Grammar usage begins between the ages of 2 and 3. Children will begin to use a subject-verb-object word order. In my opinion the best way to benefit the child's vocabulary at this stage is to actively converse with them. Expose them to as many people as possible and always encourage active communication.