Obligation, necessity and permission

______ does not have a past form. We use _______ instead.

to talk about general necessity we use _____.

____ is used to express lack of obligation.

____ is used to tell oneself what is necessary.

______ is used to talk about something that is not permitted.

_______ + ________ is used to talk about an action which was unnessary, but was performd.

to express permission it is possible to use ______ or ______ or ______.

_____ is used to express obligation, particularly when this is imposed by someone else or by external circumstances (external obligation).

______ is used to give very strong advice about what not to do.

_____ is used to give ver strong advice.

____ usually has the same meaning as 'should'.

____ is used in signs and notices indicating rules and laws

We can only use __________ when referring to a particular situation in the past.

____ is used for strong obligations imposed by the speaker (internal obligation). The speaker uses this modal verb to express his/her authority.

_____ (positive) and _____ (negative) are used to express obligation or give advice.

____ is used to express necessity.

_____ and _____ are possible for general permission in the past.

_____ + _____ is used to talk about an action which was unnecessary, but usually indicates that the action was not performed.

_______ is used to express a lack of necessity.

You can use _____ or ______ or ____ when giving permission not to do something.