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