I can theorise you can theorise she can theorise we can theorise you can theorise they can theorise
V-ing form
I can be theorising you can be theorising she can be theorising we can be theorising you can be theorising they can be theorising
Perfect
I can have theorised you can have theorised she 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 she can have been theorising we can have been theorising you can have been theorising they can have been theorising
Negation
Simple form
I can't theorise you can't theorise she can't theorise we can't theorise you can't theorise they can't theorise
V-ing form
I can't be theorising you can't be theorising she can't be theorising we can't be theorising you can't be theorising they can't be theorising
Perfect
I can't have theorised you can't have theorised she can't have theorised we can't have theorised you can't have theorised they can't have theorised
V-ing perfect
I can't have been theorising you can't have been theorising she can't have been theorising we can't have been theorising you can't have been theorising they can't have been theorising
Interrogative form
Simple form
can I theorise? can you theorise? can she theorise? can we theorise? can you theorise? can they theorise?
V-ing form
can I be theorising? can you be theorising? can she be theorising? can we be theorising? can you be theorising? can they be theorising?
Perfect
can I have theorised? can you have theorised? can she 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 she have been theorising? can we have been theorising? can you have been theorising? can they have been theorising?
Interro-negative form
Simple form
can't I theorise? can't you theorise? can't she theorise? can't we theorise? can't you theorise? can't they theorise?
V-ing form
can't I be theorising? can't you be theorising? can't she be theorising? can't we be theorising? can't you be theorising? can't they be theorising?
Perfect
can't I have theorised? can't you have theorised? can't she have theorised? can't we have theorised? can't you have theorised? can't they have theorised?
V-ing perfect
can't I have been theorising? can't you have been theorising? can't she have been theorising? can't we have been theorising? can't you have been theorising? can't they have been theorising?