I must muscle you must muscle he must muscle we must muscle you must muscle they must muscle
V-ing form
I must be muscling you must be muscling he must be muscling we must be muscling you must be muscling they must be muscling
Perfect
I must have muscled you must have muscled he must have muscled we must have muscled you must have muscled they must have muscled
V-ing perfect
I must have been muscling you must have been muscling he must have been muscling we must have been muscling you must have been muscling they must have been muscling
Negation
Simple form
I must not muscle you must not muscle he must not muscle we must not muscle you must not muscle they must not muscle
V-ing form
I must not be muscling you must not be muscling he must not be muscling we must not be muscling you must not be muscling they must not be muscling
Perfect
I must not have muscled you must not have muscled he must not have muscled we must not have muscled you must not have muscled they must not have muscled
V-ing perfect
I must not have been muscling you must not have been muscling he must not have been muscling we must not have been muscling you must not have been muscling they must not have been muscling
Interrogative form
Simple form
must I muscle? must you muscle? must he muscle? must we muscle? must you muscle? must they muscle?
V-ing form
must I be muscling? must you be muscling? must he be muscling? must we be muscling? must you be muscling? must they be muscling?
Perfect
must I have muscled? must you have muscled? must he have muscled? must we have muscled? must you have muscled? must they have muscled?
V-ing perfect
must I have been muscling? must you have been muscling? must he have been muscling? must we have been muscling? must you have been muscling? must they have been muscling?
Interro-negative form
Simple form
must I not muscle? must you not muscle? must he not muscle? must we not muscle? must you not muscle? must they not muscle?
V-ing form
must I not be muscling? must you not be muscling? must he not be muscling? must we not be muscling? must you not be muscling? must they not be muscling?
Perfect
must I not have muscled? must you not have muscled? must he not have muscled? must we not have muscled? must you not have muscled? must they not have muscled?
V-ing perfect
must I not have been muscling? must you not have been muscling? must he not have been muscling? must we not have been muscling? must you not have been muscling? must they not have been muscling?