Lots of parents worry that their child is not developing at the same rate as other children around them. Talking is one of the most common causes of this worry, as learning to talk is generally regarded as one of the most fundamental aspects of a child's development. But as cliché as it may sound, children develop at different rates, so it is usually nothing to worry about. A child that develops later than those who develop early or "on time" may seem noticeably behind, but that is by no means the case. Still, there are markers that can be identified to give you an idea of what to expect from your child and when. While these should only be viewed as guidelines, they should also help you realise that the process of learning to talk does take some time, and certain things shouldn't be expected at certain times.
Up to Nine Months
During this time, babies will not be talking at all, so don't get excited if you think you hear something that sounds like mama or dada. At this age, babies are just experimenting with sounds, but won't actually attribute any meaning to their words or the world around them. They will respond to their own name, although they probably don't really grasp the concept of a name itself.
Nine to Twelve Months
Your child probably won't be saying their first word in their first year, so that's normal. However, they will begin to understand words that are attributed to items. These are usually things like mama, dada, bottle, the name of their favourite toy, etc. They will also understand basic phrases like hello, goodbye, no, and other everyday sayings, although they won't be replicating the sounds themselves.
Twelve to Twenty-Four Months
Babies will typically say their first word at around twelve months old. This comes as their minds begin to understand that words can be attributed to objects, and later, actions. Because of the psychology behind this, children will usually speak best about objects that are right in front of them. This means that parents can help their child learn by showing the child an object and repeating its name.
This is a time when your child should really be trying to form sounds. They won't always succeed, but they should be encouraged. It is also a time when the use of gestures increases significantly. This is important, as gesturing is simply another form of communication. Although things like this may be easier for parents to miss, it is an important sign of your child's communicative abilities.
After 18 months, your child should start to understand slightly more complex phrases, but still won't be coming up with their own sentences. They should start to pick up more words, and be able to identify objects that are not directly in front of them.
Two to Three years Old
Early in their second year, children will start stringing words together to try and form sentences. They still won't understand how to use verbs or abstract concepts, but their attempts should become more ambitious and complex. This also means that they will understand better, and will start to absorb words at a much faster rate. This is the time to start really watching what people say around them, because they might not need to hear it over and over again. Age three is when things really take off, and your child should start to talk in more complete sentences and build up a large vocabulary.
While children are not an exact science and it is unreasonable to claim that all of them should develop at the same rate, these points should help you to identify where your child is in terms of their development. If they seem to be lagging slightly behind, it's no reason to worry. If they seem to be at a stage that varies considerably to where they should be, you should consider seeing a specialist.