should crackle
Regular verb: crackle - crackled- crackled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd crackle
you'd crackle
he'd crackle
we'd crackle
you'd crackle
they'd crackle 	I'd be crackling
you'd be crackling
he'd be crackling
we'd be crackling
you'd be crackling
they'd be crackling	I should've crackled
you should've crackled
he should've crackled
we should've crackled
you should've crackled
they should've crackled	I should've been crackling
you should've been crackling
he should've been crackling
we should've been crackling
you should've been crackling
they should've been crackling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't crackle
you shouldn't crackle
he shouldn't crackle
we shouldn't crackle
you shouldn't crackle
they shouldn't crackle 	I shouldn't be crackling
you shouldn't be crackling
he shouldn't be crackling
we shouldn't be crackling
you shouldn't be crackling
they shouldn't be crackling	I shouldn't have crackled
you shouldn't have crackled
he shouldn't have crackled
we shouldn't have crackled
you shouldn't have crackled
they shouldn't have crackled	I shouldn't have been crackling
you shouldn't have been crackling
he shouldn't have been crackling
we shouldn't have been crackling
you shouldn't have been crackling
they shouldn't have been crackling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I crackle?
should you crackle?
should he crackle?
should we crackle?
should you crackle?
should they crackle? 	should I be crackling?
should you be crackling?
should he be crackling?
should we be crackling?
should you be crackling?
should they be crackling? 	should I have crackled?
should you have crackled?
should he have crackled?
should we have crackled?
should you have crackled?
should they have crackled? 	should I have been crackling?
should you have been crackling?
should he have been crackling?
should we have been crackling?
should you have been crackling?
should they have been crackling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I crackle?
shouldn't you crackle?
shouldn't he crackle?
shouldn't we crackle?
shouldn't you crackle?
shouldn't they crackle? 	shouldn't I be crackling?
shouldn't you be crackling?
shouldn't he be crackling?
shouldn't we be crackling?
shouldn't you be crackling?
shouldn't they be crackling? 	shouldn't I have crackled?
shouldn't you have crackled?
shouldn't he have crackled?
shouldn't we have crackled?
shouldn't you have crackled?
shouldn't they have crackled? 	shouldn't I have been crackling?
shouldn't you have been crackling?
shouldn't he have been crackling?
shouldn't we have been crackling?
shouldn't you have been crackling?
shouldn't they have been crackling?