must thicken
Regular verb: thicken - thickened- thickened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must thicken
you must thicken
he must thicken
we must thicken
you must thicken
they must thicken 	I must be thickening
you must be thickening
he must be thickening
we must be thickening
you must be thickening
they must be thickening	I must have thickened
you must have thickened
he must have thickened
we must have thickened
you must have thickened
they must have thickened	I must have been thickening
you must have been thickening
he must have been thickening
we must have been thickening
you must have been thickening
they must have been thickening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't thicken
you mustn't thicken
he mustn't thicken
we mustn't thicken
you mustn't thicken
they mustn't thicken 	I mustn't be thickening
you mustn't be thickening
he mustn't be thickening
we mustn't be thickening
you mustn't be thickening
they mustn't be thickening	I mustn't have thickened
you mustn't have thickened
he mustn't have thickened
we mustn't have thickened
you mustn't have thickened
they mustn't have thickened	I mustn't have been thickening
you mustn't have been thickening
he mustn't have been thickening
we mustn't have been thickening
you mustn't have been thickening
they mustn't have been thickening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I thicken?
must you thicken?
must he thicken?
must we thicken?
must you thicken?
must they thicken? 	must I be thickening?
must you be thickening?
must he be thickening?
must we be thickening?
must you be thickening?
must they be thickening? 	must I have thickened?
must you have thickened?
must he have thickened?
must we have thickened?
must you have thickened?
must they have thickened? 	must I have been thickening?
must you have been thickening?
must he have been thickening?
must we have been thickening?
must you have been thickening?
must they have been thickening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I thicken?
mustn't you thicken?
mustn't he thicken?
mustn't we thicken?
mustn't you thicken?
mustn't they thicken? 	mustn't I be thickening?
mustn't you be thickening?
mustn't he be thickening?
mustn't we be thickening?
mustn't you be thickening?
mustn't they be thickening? 	mustn't I have thickened?
mustn't you have thickened?
mustn't he have thickened?
mustn't we have thickened?
mustn't you have thickened?
mustn't they have thickened? 	mustn't I have been thickening?
mustn't you have been thickening?
mustn't he have been thickening?
mustn't we have been thickening?
mustn't you have been thickening?
mustn't they have been thickening?