Model Verbs

Model Verbs

Shall

Replace "will" in the question

Ask for some opinions

Should

Replace "Shall" in the past

Predict for the future to show the wanting of the speaker

Would

Replace "will" in the past

Assumption

Invite, Request

Must

Predict in the past with almost sure: S+Must have done+ O

Have to

Mission

Compulsory

Forbid, Prevent

Less than "Must"

In (-), Have to - Must are replaced by "Had to"

Need

Lower the properties (feature) of "must"

Must I do it right now? --> No, you needn't. You can do it tomorrow

In (+), "need" -> "need(s) to V"

"Need" only with (-)

Dare

He daren't tell the truth

DARE or NEED can act as a "model V" or "main V"

Ought

Lower than "Should"

Past: Describe a disagreement for the action in the past

S+ ought to have done+ O

Predict in the past

Can/ Might (not)+ have been done+ O