Language
Receptive language includes the skills required to understand language.
Expressive language includes the skills required to communicate thoughts and feelings to others.
Generally
-One year old children should be able to understand a variety of words and should be using a few single words.
-By age two, words should be combined into two and three word phrases and sentences.
-Between the ages of three and five, children learn to carry on a conversation, ask and answer questions, follow and give directions and speak alone in the presence of others.