Speakers use pitch to give words stress. Low pitch is used to put things in the background, to treat something as old, to show anger, or as shared information. Intonation is used to signal ends and beginnings in conversation. It is used to show whether a situation is open or closed. A high or rising pitch indicates an open situation, whereas a falling pitch indicates a closed situation.
Intonation is used to show expectations.
Strong expectations are shown by low or falling pitch, whereas lack of expectations is shown by high or rising pitch. The best example here is the use of the question tag. There is a difference in the comparative force of pronunciation of stressed and unstressed syllables in English and Arabic. Sentence stress in Arabic is similar to that in English. Content words are usually stressed, and function words are usually unstressed.