could sneeze
Regular verb: sneeze - sneezed- sneezed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could sneeze
you could sneeze
he could sneeze
we could sneeze
you could sneeze
they could sneeze 	I could be sneezing
you could be sneezing
he could be sneezing
we could be sneezing
you could be sneezing
they could be sneezing	I could have sneezed
you could have sneezed
he could have sneezed
we could have sneezed
you could have sneezed
they could have sneezed	I could have been sneezing
you could have been sneezing
he could have been sneezing
we could have been sneezing
you could have been sneezing
they could have been sneezing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't sneeze
you couldn't sneeze
he couldn't sneeze
we couldn't sneeze
you couldn't sneeze
they couldn't sneeze 	I couldn't be sneezing
you couldn't be sneezing
he couldn't be sneezing
we couldn't be sneezing
you couldn't be sneezing
they couldn't be sneezing	I couldn't have sneezed
you couldn't have sneezed
he couldn't have sneezed
we couldn't have sneezed
you couldn't have sneezed
they couldn't have sneezed	I couldn't have been sneezing
you couldn't have been sneezing
he couldn't have been sneezing
we couldn't have been sneezing
you couldn't have been sneezing
they couldn't have been sneezing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I sneeze?
could you sneeze?
could he sneeze?
could we sneeze?
could you sneeze?
could they sneeze? 	could I be sneezing?
could you be sneezing?
could he be sneezing?
could we be sneezing?
could you be sneezing?
could they be sneezing? 	could I have sneezed?
could you have sneezed?
could he have sneezed?
could we have sneezed?
could you have sneezed?
could they have sneezed? 	could I have been sneezing?
could you have been sneezing?
could he have been sneezing?
could we have been sneezing?
could you have been sneezing?
could they have been sneezing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I sneeze?
couldn't you sneeze?
couldn't he sneeze?
couldn't we sneeze?
couldn't you sneeze?
couldn't they sneeze? 	couldn't I be sneezing?
couldn't you be sneezing?
couldn't he be sneezing?
couldn't we be sneezing?
couldn't you be sneezing?
couldn't they be sneezing? 	couldn't I have sneezed?
couldn't you have sneezed?
couldn't he have sneezed?
couldn't we have sneezed?
couldn't you have sneezed?
couldn't they have sneezed? 	couldn't I have been sneezing?
couldn't you have been sneezing?
couldn't he have been sneezing?
couldn't we have been sneezing?
couldn't you have been sneezing?
couldn't they have been sneezing?