Children may say some sounds the wrong way as they learn to talk. They learn some sounds earlier, like p, m, or w. Other sounds take longer to learn, like z, v, or th. Most children can say almost all speech sounds correctly by 4 years old. A child who does not say sounds by the expected ages may have a speech sound disorder. You may hear the terms "articulation disorder" and "phonological disorder" to describe speech sound disorders like this.
It is normal for young children to say the wrong sounds sometimes. For example, your child may make a "w" sound for an "r" and say "wabbit" for "rabbit." She may leave sounds out of words, such as "nana" for "banana." This is okay when she is young. It may be a problem if she keeps making these mistakes as she gets older.
You and your child may also sound different because you have an accent or dialect. This is not a speech sound disorder.
Adults can also have speech sound disorders. Some adults have problems that started when they were children. Others may have speech problems after a stroke or traumatic brain injury. To learn more about adult speech disorders after a stroke or traumatic brain injury, see apraxia of speech in adults and dysarthria.