English verb conjugation
COULD SPECIALIZE

Regular verb: specialize - specialized - specialized

Affirmation

Simple form	V-ing form
I could specialize you could specialize he could specialize we could specialize you could specialize they could specialize	I could be specializing you could be specializing he could be specializing we could be specializing you could be specializing they could be specializing
Perfect	V-ing perfect
I could have specialized you could have specialized he could have specialized we could have specialized you could have specialized they could have specialized	I could have been specializing you could have been specializing he could have been specializing we could have been specializing you could have been specializing they could have been specializing

Negation

Simple form	V-ing form
I couldn't specialize you couldn't specialize he couldn't specialize we couldn't specialize you couldn't specialize they couldn't specialize	I couldn't be specializing you couldn't be specializing he couldn't be specializing we couldn't be specializing you couldn't be specializing they couldn't be specializing
Perfect	V-ing perfect
I couldn't have specialized you couldn't have specialized he couldn't have specialized we couldn't have specialized you couldn't have specialized they couldn't have specialized	I couldn't have been specializing you couldn't have been specializing he couldn't have been specializing we couldn't have been specializing you couldn't have been specializing they couldn't have been specializing

Interrogative form

Simple form	V-ing form
could I specialize? could you specialize? could he specialize? could we specialize? could you specialize? could they specialize?	could I be specializing? could you be specializing? could he be specializing? could we be specializing? could you be specializing? could they be specializing?
Perfect	V-ing perfect
could I have specialized? could you have specialized? could he have specialized? could we have specialized? could you have specialized? could they have specialized?	could I have been specializing? could you have been specializing? could he have been specializing? could we have been specializing? could you have been specializing? could they have been specializing?

Interro-negative form

Simple form	V-ing form
couldn't I specialize? couldn't you specialize? couldn't he specialize? couldn't we specialize? couldn't you specialize? couldn't they specialize?	couldn't I be specializing? couldn't you be specializing? couldn't he be specializing? couldn't we be specializing? couldn't you be specializing? couldn't they be specializing?
Perfect	V-ing perfect
couldn't I have specialized? couldn't you have specialized? couldn't he have specialized? couldn't we have specialized? couldn't you have specialized? couldn't they have specialized?	couldn't I have been specializing? couldn't you have been specializing? couldn't he have been specializing? couldn't we have been specializing? couldn't you have been specializing? couldn't they have been specializing?