must thumbtack
Verbo regular: thumbtack - thumbtacked- thumbtacked

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must thumbtack
you must thumbtack
he must thumbtack
we must thumbtack
you must thumbtack
they must thumbtack 	I must be thumbtacking
you must be thumbtacking
he must be thumbtacking
we must be thumbtacking
you must be thumbtacking
they must be thumbtacking	I must have thumbtacked
you must have thumbtacked
he must have thumbtacked
we must have thumbtacked
you must have thumbtacked
they must have thumbtacked	I must have been thumbtacking
you must have been thumbtacking
he must have been thumbtacking
we must have been thumbtacking
you must have been thumbtacking
they must have been thumbtacking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't thumbtack
you mustn't thumbtack
he mustn't thumbtack
we mustn't thumbtack
you mustn't thumbtack
they mustn't thumbtack 	I mustn't be thumbtacking
you mustn't be thumbtacking
he mustn't be thumbtacking
we mustn't be thumbtacking
you mustn't be thumbtacking
they mustn't be thumbtacking	I mustn't have thumbtacked
you mustn't have thumbtacked
he mustn't have thumbtacked
we mustn't have thumbtacked
you mustn't have thumbtacked
they mustn't have thumbtacked	I mustn't have been thumbtacking
you mustn't have been thumbtacking
he mustn't have been thumbtacking
we mustn't have been thumbtacking
you mustn't have been thumbtacking
they mustn't have been thumbtacking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I thumbtack?
must you thumbtack?
must he thumbtack?
must we thumbtack?
must you thumbtack?
must they thumbtack? 	must I be thumbtacking?
must you be thumbtacking?
must he be thumbtacking?
must we be thumbtacking?
must you be thumbtacking?
must they be thumbtacking? 	must I have thumbtacked?
must you have thumbtacked?
must he have thumbtacked?
must we have thumbtacked?
must you have thumbtacked?
must they have thumbtacked? 	must I have been thumbtacking?
must you have been thumbtacking?
must he have been thumbtacking?
must we have been thumbtacking?
must you have been thumbtacking?
must they have been thumbtacking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I thumbtack?
mustn't you thumbtack?
mustn't he thumbtack?
mustn't we thumbtack?
mustn't you thumbtack?
mustn't they thumbtack? 	mustn't I be thumbtacking?
mustn't you be thumbtacking?
mustn't he be thumbtacking?
mustn't we be thumbtacking?
mustn't you be thumbtacking?
mustn't they be thumbtacking? 	mustn't I have thumbtacked?
mustn't you have thumbtacked?
mustn't he have thumbtacked?
mustn't we have thumbtacked?
mustn't you have thumbtacked?
mustn't they have thumbtacked? 	mustn't I have been thumbtacking?
mustn't you have been thumbtacking?
mustn't he have been thumbtacking?
mustn't we have been thumbtacking?
mustn't you have been thumbtacking?
mustn't they have been thumbtacking?