must

Saying Something Needs to Happen

Level 3

Must can express an obligation or necessity: We must leave now. It can also express an inference; the reason for the statement determines which reading fits.

How It Works

Must before a base verb can state necessity or an obligation. We must leave now can mean that the situation requires departure. Must does not change its form for the person, and its meaning comes partly from the predicate and context.

Must can also express an inference: She must be tired draws a conclusion rather than ordering her to be tired. Do not confuse the two. Negation needs care too: Must not enter forbids entry, while don't need to enter says it is unnecessary. A local speaker may choose another way to express the same practical need, without making must incorrect.

Examples (4)

  1. We must leave now.

    It is necessary for us to leave now.

  2. You must show your ticket here.

    You are required to show your ticket here.

  3. I must charge my phone.

    I need to charge my phone.

  4. She worked all night; she must be tired.

    I infer that she is tired because she worked all night.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

mustLevel 3Saying Something Needs to Happen

Learn This First

Recognize a modal plus action frame before interpreting necessity rather than ability.

Learn Next

Patterns that build on this one.