to stiffen
Regular verb: stiffen - stiffened- stiffened

Indicative 	
Present 	Present continuous 	Preterite 	Preterite continuous 	
I stiffen
you stiffen
he stiffens
we stiffen
you stiffen
they stiffen 	I'mstiffening
you'restiffening
he'sstiffening
we'restiffening
you'restiffening
they'restiffening	I stiffened
you stiffened
he stiffened
we stiffened
you stiffened
they stiffened	Iwasstiffening
youwerestiffening
hewasstiffening
wewerestiffening
youwerestiffening
theywerestiffening	
Present perfect 	Present perfect continuous 	Pluperfect 	Pluperfect continuous 	
I've stiffened
you've stiffened
he's stiffened
we've stiffened
you've stiffened
they've stiffened	I'vebeen stiffening
you'vebeen stiffening
he'sbeen stiffening
we'vebeen stiffening
you'vebeen stiffening
they'vebeen stiffening	I'd stiffened
you'd stiffened
he'd stiffened
we'd stiffened
you'd stiffened
they'd stiffened	I'd been stiffening
you'd been stiffening
he'd been stiffening
we'd been stiffening
you'd been stiffening
they'd been stiffening	
Future 	Future continuous 	Future perfect 	Future perfect continuous 	
I'll stiffen
you'll stiffen
he'll stiffen
we'll stiffen
you'll stiffen
they'll stiffen 	I'll be stiffening
you'll be stiffening
he'll be stiffening
we'll be stiffening
you'll be stiffening
they'll be stiffening	I'll have stiffened
you'll have stiffened
he'll have stiffened
we'll have stiffened
you'll have stiffened
they'll have stiffened	I'll have been stiffening
you'll have been stiffening
he'll have been stiffening
we'll have been stiffening
you'll have been stiffening
they'll have been stiffening	

Conditional 	
Present 	Present continuous 	Past 	Past continuous 	
I'd stiffen
you'd stiffen
he'd stiffen
we'd stiffen
you'd stiffen
they'd stiffen 	I'd be stiffening
you'd be stiffening
he'd be stiffening
we'd be stiffening
you'd be stiffening
they'd be stiffening	I'd have stiffened
you'd have stiffened
he'd have stiffened
we'd have stiffened
you'd have stiffened
they'd have stiffened	I'd have been stiffening
you'd have been stiffening
he'd have been stiffening
we'd have been stiffening
you'd have been stiffening
they'd have been stiffening	

Infinitive 	
Imperative 	
Infinitive 	 	Imperative 	 	
to stiffen 	 	stiffen
Let's stiffen
stiffen 	 	

Participle 	
Present 	Past 	 	 	
stiffening	stiffened