English verb conjugation
COULD DETECT

Regular verb: detect - detected - detected

Affirmation

Simple form	V-ing form
I could detect you could detect he could detect we could detect you could detect they could detect	I could be detecting you could be detecting he could be detecting we could be detecting you could be detecting they could be detecting
Perfect	V-ing perfect
I could have detected you could have detected he could have detected we could have detected you could have detected they could have detected	I could have been detecting you could have been detecting he could have been detecting we could have been detecting you could have been detecting they could have been detecting

Negation

Simple form	V-ing form
I couldn't detect you couldn't detect he couldn't detect we couldn't detect you couldn't detect they couldn't detect	I couldn't be detecting you couldn't be detecting he couldn't be detecting we couldn't be detecting you couldn't be detecting they couldn't be detecting
Perfect	V-ing perfect
I couldn't have detected you couldn't have detected he couldn't have detected we couldn't have detected you couldn't have detected they couldn't have detected	I couldn't have been detecting you couldn't have been detecting he couldn't have been detecting we couldn't have been detecting you couldn't have been detecting they couldn't have been detecting

Interrogative form

Simple form	V-ing form
could I detect? could you detect? could he detect? could we detect? could you detect? could they detect?	could I be detecting? could you be detecting? could he be detecting? could we be detecting? could you be detecting? could they be detecting?
Perfect	V-ing perfect
could I have detected? could you have detected? could he have detected? could we have detected? could you have detected? could they have detected?	could I have been detecting? could you have been detecting? could he have been detecting? could we have been detecting? could you have been detecting? could they have been detecting?

Interro-negative form

Simple form	V-ing form
couldn't I detect? couldn't you detect? couldn't he detect? couldn't we detect? couldn't you detect? couldn't they detect?	couldn't I be detecting? couldn't you be detecting? couldn't he be detecting? couldn't we be detecting? couldn't you be detecting? couldn't they be detecting?
Perfect	V-ing perfect
couldn't I have detected? couldn't you have detected? couldn't he have detected? couldn't we have detected? couldn't you have detected? couldn't they have detected?	couldn't I have been detecting? couldn't you have been detecting? couldn't he have been detecting? couldn't we have been detecting? couldn't you have been detecting? couldn't they have been detecting?