I could popularize you could popularize he could popularize we could popularize you could popularize they could popularize
V-ing form
I could be popularizing you could be popularizing he could be popularizing we could be popularizing you could be popularizing they could be popularizing
Perfect
I could have popularized you could have popularized he could have popularized we could have popularized you could have popularized they could have popularized
V-ing perfect
I could have been popularizing you could have been popularizing he could have been popularizing we could have been popularizing you could have been popularizing they could have been popularizing
Negation
Simple form
I couldn't popularize you couldn't popularize he couldn't popularize we couldn't popularize you couldn't popularize they couldn't popularize
V-ing form
I couldn't be popularizing you couldn't be popularizing he couldn't be popularizing we couldn't be popularizing you couldn't be popularizing they couldn't be popularizing
Perfect
I couldn't have popularized you couldn't have popularized he couldn't have popularized we couldn't have popularized you couldn't have popularized they couldn't have popularized
V-ing perfect
I couldn't have been popularizing you couldn't have been popularizing he couldn't have been popularizing we couldn't have been popularizing you couldn't have been popularizing they couldn't have been popularizing
Interrogative form
Simple form
could I popularize? could you popularize? could he popularize? could we popularize? could you popularize? could they popularize?
V-ing form
could I be popularizing? could you be popularizing? could he be popularizing? could we be popularizing? could you be popularizing? could they be popularizing?
Perfect
could I have popularized? could you have popularized? could he have popularized? could we have popularized? could you have popularized? could they have popularized?
V-ing perfect
could I have been popularizing? could you have been popularizing? could he have been popularizing? could we have been popularizing? could you have been popularizing? could they have been popularizing?
Interro-negative form
Simple form
couldn't I popularize? couldn't you popularize? couldn't he popularize? couldn't we popularize? couldn't you popularize? couldn't they popularize?
V-ing form
couldn't I be popularizing? couldn't you be popularizing? couldn't he be popularizing? couldn't we be popularizing? couldn't you be popularizing? couldn't they be popularizing?
Perfect
couldn't I have popularized? couldn't you have popularized? couldn't he have popularized? couldn't we have popularized? couldn't you have popularized? couldn't they have popularized?
V-ing perfect
couldn't I have been popularizing? couldn't you have been popularizing? couldn't he have been popularizing? couldn't we have been popularizing? couldn't you have been popularizing? couldn't they have been popularizing?