There are many symptoms of autism, including repetitive behaviors, physical issues, medical issues, nonverbal communication challenges and social challenges. The autism spectrum is quite large, and some people will only have a few symptoms and be mildly autistic, while others have many symptoms and are severely autistic.
Autism spectrum disorders (ASD) all have the same social interaction problems and communication problems, as well as the need to participate in repetitive behaviors. Social challenges can be seen in autistic infants when they are not interested in their caretakers and do not look at their caretakers' faces or pay attention to voices. Toddlers often ignore their names and do not initiate games with others, often playing on their own.
When children are autistic, they also typically have a difficult time babbling and starting to speak. They have language delays and speak much later. As adults, autistic people will often be nonverbal or will only communicate with certain people. Children who are only slightly affected by autism may not see as many of these language learning delays and may be verbal, but they may talk in monologues on a particular subject rather than follow the natural give-and-take in a conversation.
Repetitive behaviors can be seen when children want to play with toys in a limited way, such as lining up stuffed animals or trucks in a row over and over again. These children are not imaginative, and do not think of playing with their toys in a pretend play way.