English verb conjugation
COULD TWITTER

Regular verb: twitter - twittered - twittered

Affirmation

Simple form	V-ing form
I could twitter you could twitter he could twitter we could twitter you could twitter they could twitter	I could be twittering you could be twittering he could be twittering we could be twittering you could be twittering they could be twittering
Perfect	V-ing perfect
I could have twittered you could have twittered he could have twittered we could have twittered you could have twittered they could have twittered	I could have been twittering you could have been twittering he could have been twittering we could have been twittering you could have been twittering they could have been twittering

Negation

Simple form	V-ing form
I couldn't twitter you couldn't twitter he couldn't twitter we couldn't twitter you couldn't twitter they couldn't twitter	I couldn't be twittering you couldn't be twittering he couldn't be twittering we couldn't be twittering you couldn't be twittering they couldn't be twittering
Perfect	V-ing perfect
I couldn't have twittered you couldn't have twittered he couldn't have twittered we couldn't have twittered you couldn't have twittered they couldn't have twittered	I couldn't have been twittering you couldn't have been twittering he couldn't have been twittering we couldn't have been twittering you couldn't have been twittering they couldn't have been twittering

Interrogative form

Simple form	V-ing form
could I twitter? could you twitter? could he twitter? could we twitter? could you twitter? could they twitter?	could I be twittering? could you be twittering? could he be twittering? could we be twittering? could you be twittering? could they be twittering?
Perfect	V-ing perfect
could I have twittered? could you have twittered? could he have twittered? could we have twittered? could you have twittered? could they have twittered?	could I have been twittering? could you have been twittering? could he have been twittering? could we have been twittering? could you have been twittering? could they have been twittering?

Interro-negative form

Simple form	V-ing form
couldn't I twitter? couldn't you twitter? couldn't he twitter? couldn't we twitter? couldn't you twitter? couldn't they twitter?	couldn't I be twittering? couldn't you be twittering? couldn't he be twittering? couldn't we be twittering? couldn't you be twittering? couldn't they be twittering?
Perfect	V-ing perfect
couldn't I have twittered? couldn't you have twittered? couldn't he have twittered? couldn't we have twittered? couldn't you have twittered? couldn't they have twittered?	couldn't I have been twittering? couldn't you have been twittering? couldn't he have been twittering? couldn't we have been twittering? couldn't you have been twittering? couldn't they have been twittering?