I can endeavour you can endeavour he can endeavour we can endeavour you can endeavour they can endeavour
V-ing form
I can be endeavouring you can be endeavouring he can be endeavouring we can be endeavouring you can be endeavouring they can be endeavouring
Perfect
I can have endeavoured you can have endeavoured he can have endeavoured we can have endeavoured you can have endeavoured they can have endeavoured
V-ing perfect
I can have been endeavouring you can have been endeavouring he can have been endeavouring we can have been endeavouring you can have been endeavouring they can have been endeavouring
Negation
Simple form
I cannot endeavour you cannot endeavour he cannot endeavour we cannot endeavour you cannot endeavour they cannot endeavour
V-ing form
I cannot be endeavouring you cannot be endeavouring he cannot be endeavouring we cannot be endeavouring you cannot be endeavouring they cannot be endeavouring
Perfect
I cannot have endeavoured you cannot have endeavoured he cannot have endeavoured we cannot have endeavoured you cannot have endeavoured they cannot have endeavoured
V-ing perfect
I cannot have been endeavouring you cannot have been endeavouring he cannot have been endeavouring we cannot have been endeavouring you cannot have been endeavouring they cannot have been endeavouring
Interrogative form
Simple form
can I endeavour? can you endeavour? can he endeavour? can we endeavour? can you endeavour? can they endeavour?
V-ing form
can I be endeavouring? can you be endeavouring? can he be endeavouring? can we be endeavouring? can you be endeavouring? can they be endeavouring?
Perfect
can I have endeavoured? can you have endeavoured? can he have endeavoured? can we have endeavoured? can you have endeavoured? can they have endeavoured?
V-ing perfect
can I have been endeavouring? can you have been endeavouring? can he have been endeavouring? can we have been endeavouring? can you have been endeavouring? can they have been endeavouring?
Interro-negative form
Simple form
can I not endeavour? can you not endeavour? can he not endeavour? can we not endeavour? can you not endeavour? can they not endeavour?
V-ing form
can I not be endeavouring? can you not be endeavouring? can he not be endeavouring? can we not be endeavouring? can you not be endeavouring? can they not be endeavouring?
Perfect
can I not have endeavoured? can you not have endeavoured? can he not have endeavoured? can we not have endeavoured? can you not have endeavoured? can they not have endeavoured?
V-ing perfect
can I not have been endeavouring? can you not have been endeavouring? can he not have been endeavouring? can we not have been endeavouring? can you not have been endeavouring? can they not have been endeavouring?