should mask
Regular verb: mask - masked- masked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should mask
you should mask
he should mask
we should mask
you should mask
they should mask 	I should be masking
you should be masking
he should be masking
we should be masking
you should be masking
they should be masking	I should have masked
you should have masked
he should have masked
we should have masked
you should have masked
they should have masked	I should have been masking
you should have been masking
he should have been masking
we should have been masking
you should have been masking
they should have been masking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not mask
you should not mask
he should not mask
we should not mask
you should not mask
they should not mask 	I should not be masking
you should not be masking
he should not be masking
we should not be masking
you should not be masking
they should not be masking	I should not have masked
you should not have masked
he should not have masked
we should not have masked
you should not have masked
they should not have masked	I should not have been masking
you should not have been masking
he should not have been masking
we should not have been masking
you should not have been masking
they should not have been masking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I mask?
should you mask?
should he mask?
should we mask?
should you mask?
should they mask? 	should I be masking?
should you be masking?
should he be masking?
should we be masking?
should you be masking?
should they be masking? 	should I have masked?
should you have masked?
should he have masked?
should we have masked?
should you have masked?
should they have masked? 	should I have been masking?
should you have been masking?
should he have been masking?
should we have been masking?
should you have been masking?
should they have been masking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not mask?
should you not mask?
should he not mask?
should we not mask?
should you not mask?
should they not mask? 	should I not be masking?
should you not be masking?
should he not be masking?
should we not be masking?
should you not be masking?
should they not be masking? 	should I not have masked?
should you not have masked?
should he not have masked?
should we not have masked?
should you not have masked?
should they not have masked? 	should I not have been masking?
should you not have been masking?
should he not have been masking?
should we not have been masking?
should you not have been masking?
should they not have been masking?