must skin
Regular verb: skin - skinned- skinned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must skin
you must skin
she must skin
we must skin
you must skin
they must skin 	I must be skinning
you must be skinning
she must be skinning
we must be skinning
you must be skinning
they must be skinning	I must have skinned
you must have skinned
she must have skinned
we must have skinned
you must have skinned
they must have skinned	I must have been skinning
you must have been skinning
she must have been skinning
we must have been skinning
you must have been skinning
they must have been skinning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not skin
you must not skin
she must not skin
we must not skin
you must not skin
they must not skin 	I must not be skinning
you must not be skinning
she must not be skinning
we must not be skinning
you must not be skinning
they must not be skinning	I must not have skinned
you must not have skinned
she must not have skinned
we must not have skinned
you must not have skinned
they must not have skinned	I must not have been skinning
you must not have been skinning
she must not have been skinning
we must not have been skinning
you must not have been skinning
they must not have been skinning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I skin?
must you skin?
must she skin?
must we skin?
must you skin?
must they skin? 	must I be skinning?
must you be skinning?
must she be skinning?
must we be skinning?
must you be skinning?
must they be skinning? 	must I have skinned?
must you have skinned?
must she have skinned?
must we have skinned?
must you have skinned?
must they have skinned? 	must I have been skinning?
must you have been skinning?
must she have been skinning?
must we have been skinning?
must you have been skinning?
must they have been skinning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not skin?
must you not skin?
must she not skin?
must we not skin?
must you not skin?
must they not skin? 	must I not be skinning?
must you not be skinning?
must she not be skinning?
must we not be skinning?
must you not be skinning?
must they not be skinning? 	must I not have skinned?
must you not have skinned?
must she not have skinned?
must we not have skinned?
must you not have skinned?
must they not have skinned? 	must I not have been skinning?
must you not have been skinning?
must she not have been skinning?
must we not have been skinning?
must you not have been skinning?
must they not have been skinning?