I could quarantine you could quarantine she could quarantine we could quarantine you could quarantine they could quarantine
V-ing form
I could be quarantining you could be quarantining she could be quarantining we could be quarantining you could be quarantining they could be quarantining
Perfect
I could have quarantined you could have quarantined she could have quarantined we could have quarantined you could have quarantined they could have quarantined
V-ing perfect
I could have been quarantining you could have been quarantining she could have been quarantining we could have been quarantining you could have been quarantining they could have been quarantining
Negation
Simple form
I could not quarantine you could not quarantine she could not quarantine we could not quarantine you could not quarantine they could not quarantine
V-ing form
I could not be quarantining you could not be quarantining she could not be quarantining we could not be quarantining you could not be quarantining they could not be quarantining
Perfect
I could not have quarantined you could not have quarantined she could not have quarantined we could not have quarantined you could not have quarantined they could not have quarantined
V-ing perfect
I could not have been quarantining you could not have been quarantining she could not have been quarantining we could not have been quarantining you could not have been quarantining they could not have been quarantining
Interrogative form
Simple form
could I quarantine? could you quarantine? could she quarantine? could we quarantine? could you quarantine? could they quarantine?
V-ing form
could I be quarantining? could you be quarantining? could she be quarantining? could we be quarantining? could you be quarantining? could they be quarantining?
Perfect
could I have quarantined? could you have quarantined? could she have quarantined? could we have quarantined? could you have quarantined? could they have quarantined?
V-ing perfect
could I have been quarantining? could you have been quarantining? could she have been quarantining? could we have been quarantining? could you have been quarantining? could they have been quarantining?
Interro-negative form
Simple form
could I not quarantine? could you not quarantine? could she not quarantine? could we not quarantine? could you not quarantine? could they not quarantine?
V-ing form
could I not be quarantining? could you not be quarantining? could she not be quarantining? could we not be quarantining? could you not be quarantining? could they not be quarantining?
Perfect
could I not have quarantined? could you not have quarantined? could she not have quarantined? could we not have quarantined? could you not have quarantined? could they not have quarantined?
V-ing perfect
could I not have been quarantining? could you not have been quarantining? could she not have been quarantining? could we not have been quarantining? could you not have been quarantining? could they not have been quarantining?