When children reach around 3 years old they normally start to talk after having taking a number of different steps or stages on learning how to talk. Around a year they might say some words after babbling long term, they respond if you call their names. A child may also point with its index finger if they want something or even shake their head if they wish to avoid something. Some children might talk with sentences even before than 3 years old. Girls mostly talk before boys, and children who live in one language home tend to talk earlier than other children who lives in a home where several languages are heard.
It is one of the signs speech and language problem that cause talking late with an autistic child. They often speaks late or they stars to talk and lose their talks after autism , uses metallic abnormal tone, does not understand any simple sentences, repeats the same words again and again, does not respond their name, doesn’t respond to your question and mostly answers with the question instead of answering, they mostly do grammar mistakes, they don’t point the things they don’t know how to use their body language. On the other hand some of them just makes noises not even words.
Talking late should not call you just autism; your child might have some other problems like language disorder, hearing problem or some other developmental problem. Talking late one of the most common problem in autism spectrum. The best thing you can do correct diagnosis and good treatment like speech and language therapy.
There are so many types of speech threapies you can reach. If you find the best one which suits your child then you can find a way to connect his/her world. Sign language or PECS or some others can be the way to communicate. There is always a way to communicate.