could ultrafilter
Regular verb: ultrafilter - ultrafiltered- ultrafiltered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could ultrafilter
you could ultrafilter
he could ultrafilter
we could ultrafilter
you could ultrafilter
they could ultrafilter 	I could be ultrafiltering
you could be ultrafiltering
he could be ultrafiltering
we could be ultrafiltering
you could be ultrafiltering
they could be ultrafiltering	I could have ultrafiltered
you could have ultrafiltered
he could have ultrafiltered
we could have ultrafiltered
you could have ultrafiltered
they could have ultrafiltered	I could have been ultrafiltering
you could have been ultrafiltering
he could have been ultrafiltering
we could have been ultrafiltering
you could have been ultrafiltering
they could have been ultrafiltering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't ultrafilter
you couldn't ultrafilter
he couldn't ultrafilter
we couldn't ultrafilter
you couldn't ultrafilter
they couldn't ultrafilter 	I couldn't be ultrafiltering
you couldn't be ultrafiltering
he couldn't be ultrafiltering
we couldn't be ultrafiltering
you couldn't be ultrafiltering
they couldn't be ultrafiltering	I couldn't have ultrafiltered
you couldn't have ultrafiltered
he couldn't have ultrafiltered
we couldn't have ultrafiltered
you couldn't have ultrafiltered
they couldn't have ultrafiltered	I couldn't have been ultrafiltering
you couldn't have been ultrafiltering
he couldn't have been ultrafiltering
we couldn't have been ultrafiltering
you couldn't have been ultrafiltering
they couldn't have been ultrafiltering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I ultrafilter?
could you ultrafilter?
could he ultrafilter?
could we ultrafilter?
could you ultrafilter?
could they ultrafilter? 	could I be ultrafiltering?
could you be ultrafiltering?
could he be ultrafiltering?
could we be ultrafiltering?
could you be ultrafiltering?
could they be ultrafiltering? 	could I have ultrafiltered?
could you have ultrafiltered?
could he have ultrafiltered?
could we have ultrafiltered?
could you have ultrafiltered?
could they have ultrafiltered? 	could I have been ultrafiltering?
could you have been ultrafiltering?
could he have been ultrafiltering?
could we have been ultrafiltering?
could you have been ultrafiltering?
could they have been ultrafiltering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I ultrafilter?
couldn't you ultrafilter?
couldn't he ultrafilter?
couldn't we ultrafilter?
couldn't you ultrafilter?
couldn't they ultrafilter? 	couldn't I be ultrafiltering?
couldn't you be ultrafiltering?
couldn't he be ultrafiltering?
couldn't we be ultrafiltering?
couldn't you be ultrafiltering?
couldn't they be ultrafiltering? 	couldn't I have ultrafiltered?
couldn't you have ultrafiltered?
couldn't he have ultrafiltered?
couldn't we have ultrafiltered?
couldn't you have ultrafiltered?
couldn't they have ultrafiltered? 	couldn't I have been ultrafiltering?
couldn't you have been ultrafiltering?
couldn't he have been ultrafiltering?
couldn't we have been ultrafiltering?
couldn't you have been ultrafiltering?
couldn't they have been ultrafiltering?