You need to see a speech therapist, when you are having following problems
- pronunciation problems
- communication problems
- understanding, comprehension issues
- language disorder

Yes, a speech therapist can help to manage autistic children by improving their communication and language. They help in improving articulation, communicating verbally and non verbally, conversational and comprehension skills.

Stammering can be corrected by the treatment from a speech therapist as it teaches to reduce speed of speech and notice stammering.

No, a speech therapist doesn't prescribe medications. They help in developing language, improving communication and articulation of speech.

To become a speech therapist, a degree or diploma in speech therapy is required after completion of any basic undergraduate degree in life sciences.