I'll be stiffening you'll be stiffening he'll be stiffening we'll be stiffening you'll be stiffening they'll be stiffening
Futuro perfecto
I'll have stiffened you'll have stiffened he'll have stiffened we'll have stiffened you'll have stiffened they'll have stiffened
Futuro perfecto contínuo
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
I'd be stiffening you'd be stiffening he'd be stiffening we'd be stiffening you'd be stiffening they'd be stiffening
Passado
I'd have stiffened you'd have stiffened he'd have stiffened we'd have stiffened you'd have stiffened they'd have stiffened
Passado continuo
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