English verb conjugation
SHOULD TOUGHEN

Regular verb: toughen - toughened - toughened

Affirmation

Simple form	V-ing form
I'd toughen you'd toughen he'd toughen we'd toughen you'd toughen they'd toughen	I'd be toughening you'd be toughening he'd be toughening we'd be toughening you'd be toughening they'd be toughening
Perfect	V-ing perfect
I should've toughened you should've toughened he should've toughened we should've toughened you should've toughened they should've toughened	I should've been toughening you should've been toughening he should've been toughening we should've been toughening you should've been toughening they should've been toughening

Negation

Simple form	V-ing form
I shouldn't toughen you shouldn't toughen he shouldn't toughen we shouldn't toughen you shouldn't toughen they shouldn't toughen	I shouldn't be toughening you shouldn't be toughening he shouldn't be toughening we shouldn't be toughening you shouldn't be toughening they shouldn't be toughening
Perfect	V-ing perfect
I shouldn't have toughened you shouldn't have toughened he shouldn't have toughened we shouldn't have toughened you shouldn't have toughened they shouldn't have toughened	I shouldn't have been toughening you shouldn't have been toughening he shouldn't have been toughening we shouldn't have been toughening you shouldn't have been toughening they shouldn't have been toughening

Interrogative form

Simple form	V-ing form
should I toughen? should you toughen? should he toughen? should we toughen? should you toughen? should they toughen?	should I be toughening? should you be toughening? should he be toughening? should we be toughening? should you be toughening? should they be toughening?
Perfect	V-ing perfect
should I have toughened? should you have toughened? should he have toughened? should we have toughened? should you have toughened? should they have toughened?	should I have been toughening? should you have been toughening? should he have been toughening? should we have been toughening? should you have been toughening? should they have been toughening?

Interro-negative form

Simple form	V-ing form
shouldn't I toughen? shouldn't you toughen? shouldn't he toughen? shouldn't we toughen? shouldn't you toughen? shouldn't they toughen?	shouldn't I be toughening? shouldn't you be toughening? shouldn't he be toughening? shouldn't we be toughening? shouldn't you be toughening? shouldn't they be toughening?
Perfect	V-ing perfect
shouldn't I have toughened? shouldn't you have toughened? shouldn't he have toughened? shouldn't we have toughened? shouldn't you have toughened? shouldn't they have toughened?	shouldn't I have been toughening? shouldn't you have been toughening? shouldn't he have been toughening? shouldn't we have been toughening? shouldn't you have been toughening? shouldn't they have been toughening?