One example of Child Directed Speech used by Tom's mother is Extension. This is apparent where in reply to Tom's utterance "it make noises", his mother has said "it makes noises?" The extension of the word 'make' to 'makes' adds an inflection to the main verb which is what is required when referring to a noun in third person, such as "it". However the subject-to-verb-to-object correlation can prove difficult for children to grasp, which is why he has struggled with it in this instance. The reason she has used expansion is because she is able to subtlely correct Tom's utterance without overtly highlighting his virtuous error. She uses positive reinforcement to correct Tom's incorrect utterance because she doesn't want him to lose any confidence in speaking, as Tom could be more reluctant to speak as a result. This is similar to Skinner who conveyed the idea that a child should learn language as they would learn their behaviour, where it comes naturally after trial and error for example. This way the mother can teach the correct verb formation in a subtle, positive way. This is done through replying with a question-like tone to not seem like she holds the power in the conversation, because the focus is solely on Tom. This clearly indicates a method of Child Directed Speech through Extension developing Tom's language because Tom is not only learning the correct use of the inflection but is also not losing any confidence in speaking to his mother and therefore can still gain sufficient experience of a conversation, therefore developing his language.