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 could not laughter you could not laughter he could not laughter we could not laughter you could not laughter they could not laughter
V-ing form
I could not be laughtering you could not be laughtering he could not be laughtering we could not be laughtering you could not be laughtering they could not be laughtering
Perfect
I could not have laughtered you could not have laughtered he could not have laughtered we could not have laughtered you could not have laughtered they could not have laughtered
V-ing perfect
I could not have been laughtering you could not have been laughtering he could not have been laughtering we could not have been laughtering you could not have been laughtering they could not 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
could I not laughter? could you not laughter? could he not laughter? could we not laughter? could you not laughter? could they not laughter?
V-ing form
could I not be laughtering? could you not be laughtering? could he not be laughtering? could we not be laughtering? could you not be laughtering? could they not be laughtering?
Perfect
could I not have laughtered? could you not have laughtered? could he not have laughtered? could we not have laughtered? could you not have laughtered? could they not have laughtered?
V-ing perfect
could I not have been laughtering? could you not have been laughtering? could he not have been laughtering? could we not have been laughtering? could you not have been laughtering? could they not have been laughtering?