I can theorise you can theorise he can theorise we can theorise you can theorise they can theorise
V-ing form
I can be theorising you can be theorising he can be theorising we can be theorising you can be theorising they can be theorising
Perfect
I can have theorised you can have theorised he can have theorised we can have theorised you can have theorised they can have theorised
V-ing perfect
I can have been theorising you can have been theorising he can have been theorising we can have been theorising you can have been theorising they can have been theorising
Negation
Simple form
I cannot theorise you cannot theorise he cannot theorise we cannot theorise you cannot theorise they cannot theorise
V-ing form
I cannot be theorising you cannot be theorising he cannot be theorising we cannot be theorising you cannot be theorising they cannot be theorising
Perfect
I cannot have theorised you cannot have theorised he cannot have theorised we cannot have theorised you cannot have theorised they cannot have theorised
V-ing perfect
I cannot have been theorising you cannot have been theorising he cannot have been theorising we cannot have been theorising you cannot have been theorising they cannot have been theorising
Interrogative form
Simple form
can I theorise? can you theorise? can he theorise? can we theorise? can you theorise? can they theorise?
V-ing form
can I be theorising? can you be theorising? can he be theorising? can we be theorising? can you be theorising? can they be theorising?
Perfect
can I have theorised? can you have theorised? can he have theorised? can we have theorised? can you have theorised? can they have theorised?
V-ing perfect
can I have been theorising? can you have been theorising? can he have been theorising? can we have been theorising? can you have been theorising? can they have been theorising?
Interro-negative form
Simple form
can I not theorise? can you not theorise? can he not theorise? can we not theorise? can you not theorise? can they not theorise?
V-ing form
can I not be theorising? can you not be theorising? can he not be theorising? can we not be theorising? can you not be theorising? can they not be theorising?
Perfect
can I not have theorised? can you not have theorised? can he not have theorised? can we not have theorised? can you not have theorised? can they not have theorised?
V-ing perfect
can I not have been theorising? can you not have been theorising? can he not have been theorising? can we not have been theorising? can you not have been theorising? can they not have been theorising?