Final answer:
In an informal talk or speech, intonation refers to the changing pitch of a person's voice when speaking.
Step-by-step explanation:
In an informal talk or speech, intonation refers to the changing pitch of a person's voice when speaking. It involves variations in the pitch, rhythm, and stress of words and phrases to convey meaning and express emotions. For example, when someone asks a question, their voice often rises at the end of the sentence to indicate the interrogative tone.
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