Now we turn our attention to the intonation patterns. Let me define 'intonation' by explaining the terms 'pitch' first. 'Pitch' is the musical note on which we speak. Intonation is basically the pitches in a sentence. Generally, we have the high pitch (which we represent with '3'), the normal pitch (which we represent with '2'), and the low pitch (which we represent with '1'). To make the idea clearer, I'd like to apply the pitches we talked about with lines at the different levels. With the '3', we can draw the line above the letters. With the '2', the line goes under the letters. And with the '1', the line is drawn below the letters.

It would be better to explain this representation along with the intonation patterns.

Intonation patterns: We can break down intonation patterns into two major types: Final intonation pattern and Non-final intonation pattern.

Final intonation pattern: if the sentence is one simple sentence, it is either 2-3-1 or 2-3 (2-3-3) pattern.

1. 2-3-1: Statement, declarative, command sentence, WH question.
I have never heard from Jim since Christmas.
2. 2-3 or 2-3-3: Yes-no questions, WH questions when the speaker ask for the repetition of the information
Will you call John for me?
A: I saw John at the party last night.
B: When did you see him?

Non-final intonation pattern: if the sentence contains punctuation marks i.e. colon (:), semicolon (;), commas (,), or subordinators (when, before, after etc.) or coordinators (but, and, or etc.)

1. 2-3-2, 2-3-1: declarative with subordinators
Anne came after John left.

2. 2-3-2, 2-3: 1. statements followed by yes-no questions, 2. greetings, and 3. WH questions directed to someone
1. If you see John, will you ask him to call me?
2. Good morning, Dr. Smith.
3. Why are you late, John?

3. 2-3, 2-3-1: Alternative questions
Would you like to see him in the morning or in the afternoon?