Children develop language skills at their own pace, and there is a wide range of normal development. For example, it is considered normal to have two 18 month old children, one of whom says 9 words and another who says 50. This is similar to how children develop skills to crawl, walk and read. Also, at 18 months, you should notice that your child is talking more than using gestures.
Two-word utterances should start to emerge just before age 2, and should become consistent at the 2 year mark. By this time, children should have at least a 50-word vocabulary and always be using new words.
Between 2 and 3 years old, sentence length should increase and you should notice more of a variety of words (verbs, pronouns, adjectives, prepositions, etc.).
If you notice your child has difficulty answering questions, “finding” words, following directions, or repeats what others say, it is appropriate to seek out a speech therapist for a language evaluation.
Sometimes pediatricians don’t know your child as you do, and to calm your fears and possibly help your child’s progress, it is advisable to seek out an evaluation with a licensed, ASHA certified speech-language pathologist.