Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could laughter you could laughter he could laughter we could laughter you could laughter they could laughter
V-ing form
I could be laughtering you could be laughtering he could be laughtering we could be laughtering you could be laughtering they could be laughtering
Perfect
I could have laughtered you could have laughtered he could have laughtered we could have laughtered you could have laughtered they could have laughtered
V-ing perfect
I could have been laughtering you could have been laughtering he could have been laughtering we could have been laughtering you could have been laughtering they could have been laughtering
Negation
Simple form
I couldn't laughter you couldn't laughter he couldn't laughter we couldn't laughter you couldn't laughter they couldn't laughter
V-ing form
I couldn't be laughtering you couldn't be laughtering he couldn't be laughtering we couldn't be laughtering you couldn't be laughtering they couldn't be laughtering
Perfect
I couldn't have laughtered you couldn't have laughtered he couldn't have laughtered we couldn't have laughtered you couldn't have laughtered they couldn't have laughtered
V-ing perfect
I couldn't have been laughtering you couldn't have been laughtering he couldn't have been laughtering we couldn't have been laughtering you couldn't have been laughtering they couldn't have been laughtering
Interrogative form
Simple form
could I laughter? could you laughter? could he laughter? could we laughter? could you laughter? could they laughter?
V-ing form
could I be laughtering? could you be laughtering? could he be laughtering? could we be laughtering? could you be laughtering? could they be laughtering?
Perfect
could I have laughtered? could you have laughtered? could he have laughtered? could we have laughtered? could you have laughtered? could they have laughtered?
V-ing perfect
could I have been laughtering? could you have been laughtering? could he have been laughtering? could we have been laughtering? could you have been laughtering? could they have been laughtering?
Interro-negative form
Simple form
couldn't I laughter? couldn't you laughter? couldn't he laughter? couldn't we laughter? couldn't you laughter? couldn't they laughter?
V-ing form
couldn't I be laughtering? couldn't you be laughtering? couldn't he be laughtering? couldn't we be laughtering? couldn't you be laughtering? couldn't they be laughtering?
Perfect
couldn't I have laughtered? couldn't you have laughtered? couldn't he have laughtered? couldn't we have laughtered? couldn't you have laughtered? couldn't they have laughtered?
V-ing perfect
couldn't I have been laughtering? couldn't you have been laughtering? couldn't he have been laughtering? couldn't we have been laughtering? couldn't you have been laughtering? couldn't they have been laughtering?