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