can prewarn
Regular verb: prewarn - prewarned- prewarned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can prewarn
you can prewarn
he can prewarn
we can prewarn
you can prewarn
they can prewarn 	I can be prewarning
you can be prewarning
he can be prewarning
we can be prewarning
you can be prewarning
they can be prewarning	I can have prewarned
you can have prewarned
he can have prewarned
we can have prewarned
you can have prewarned
they can have prewarned	I can have been prewarning
you can have been prewarning
he can have been prewarning
we can have been prewarning
you can have been prewarning
they can have been prewarning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't prewarn
you can't prewarn
he can't prewarn
we can't prewarn
you can't prewarn
they can't prewarn 	I can't be prewarning
you can't be prewarning
he can't be prewarning
we can't be prewarning
you can't be prewarning
they can't be prewarning	I can't have prewarned
you can't have prewarned
he can't have prewarned
we can't have prewarned
you can't have prewarned
they can't have prewarned	I can't have been prewarning
you can't have been prewarning
he can't have been prewarning
we can't have been prewarning
you can't have been prewarning
they can't have been prewarning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I prewarn?
can you prewarn?
can he prewarn?
can we prewarn?
can you prewarn?
can they prewarn? 	can I be prewarning?
can you be prewarning?
can he be prewarning?
can we be prewarning?
can you be prewarning?
can they be prewarning? 	can I have prewarned?
can you have prewarned?
can he have prewarned?
can we have prewarned?
can you have prewarned?
can they have prewarned? 	can I have been prewarning?
can you have been prewarning?
can he have been prewarning?
can we have been prewarning?
can you have been prewarning?
can they have been prewarning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I prewarn?
can't you prewarn?
can't he prewarn?
can't we prewarn?
can't you prewarn?
can't they prewarn? 	can't I be prewarning?
can't you be prewarning?
can't he be prewarning?
can't we be prewarning?
can't you be prewarning?
can't they be prewarning? 	can't I have prewarned?
can't you have prewarned?
can't he have prewarned?
can't we have prewarned?
can't you have prewarned?
can't they have prewarned? 	can't I have been prewarning?
can't you have been prewarning?
can't he have been prewarning?
can't we have been prewarning?
can't you have been prewarning?
can't they have been prewarning?