could lemmatise
Regular verb: lemmatise - lemmatised- lemmatised

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could lemmatise
you could lemmatise
he could lemmatise
we could lemmatise
you could lemmatise
they could lemmatise 	I could be lemmatising
you could be lemmatising
he could be lemmatising
we could be lemmatising
you could be lemmatising
they could be lemmatising	I could have lemmatised
you could have lemmatised
he could have lemmatised
we could have lemmatised
you could have lemmatised
they could have lemmatised	I could have been lemmatising
you could have been lemmatising
he could have been lemmatising
we could have been lemmatising
you could have been lemmatising
they could have been lemmatising	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't lemmatise
you couldn't lemmatise
he couldn't lemmatise
we couldn't lemmatise
you couldn't lemmatise
they couldn't lemmatise 	I couldn't be lemmatising
you couldn't be lemmatising
he couldn't be lemmatising
we couldn't be lemmatising
you couldn't be lemmatising
they couldn't be lemmatising	I couldn't have lemmatised
you couldn't have lemmatised
he couldn't have lemmatised
we couldn't have lemmatised
you couldn't have lemmatised
they couldn't have lemmatised	I couldn't have been lemmatising
you couldn't have been lemmatising
he couldn't have been lemmatising
we couldn't have been lemmatising
you couldn't have been lemmatising
they couldn't have been lemmatising	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I lemmatise?
could you lemmatise?
could he lemmatise?
could we lemmatise?
could you lemmatise?
could they lemmatise? 	could I be lemmatising?
could you be lemmatising?
could he be lemmatising?
could we be lemmatising?
could you be lemmatising?
could they be lemmatising? 	could I have lemmatised?
could you have lemmatised?
could he have lemmatised?
could we have lemmatised?
could you have lemmatised?
could they have lemmatised? 	could I have been lemmatising?
could you have been lemmatising?
could he have been lemmatising?
could we have been lemmatising?
could you have been lemmatising?
could they have been lemmatising? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I lemmatise?
couldn't you lemmatise?
couldn't he lemmatise?
couldn't we lemmatise?
couldn't you lemmatise?
couldn't they lemmatise? 	couldn't I be lemmatising?
couldn't you be lemmatising?
couldn't he be lemmatising?
couldn't we be lemmatising?
couldn't you be lemmatising?
couldn't they be lemmatising? 	couldn't I have lemmatised?
couldn't you have lemmatised?
couldn't he have lemmatised?
couldn't we have lemmatised?
couldn't you have lemmatised?
couldn't they have lemmatised? 	couldn't I have been lemmatising?
couldn't you have been lemmatising?
couldn't he have been lemmatising?
couldn't we have been lemmatising?
couldn't you have been lemmatising?
couldn't they have been lemmatising?