must

From Wiktionary

[change] Pronunciation

• (stressed) IPA: /mʌst/, SAMPA: /mVst/
• (unstressed) IPA: /məs(t)/, SAMPA: /m@s(t)/
•  Audio (US)^{help, file}

[change] Verb

Simple present must

Simple past --

Negative mustn't

1. Must is usually used to tell someone they have no choice about doing something because it is important or because of a rule or law.

   She must get her medicine soon or she will die.