can enter
Regular verb: enter - entered- entered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can enter
you can enter
he can enter
we can enter
you can enter
they can enter 	I can be entering
you can be entering
he can be entering
we can be entering
you can be entering
they can be entering	I can have entered
you can have entered
he can have entered
we can have entered
you can have entered
they can have entered	I can have been entering
you can have been entering
he can have been entering
we can have been entering
you can have been entering
they can have been entering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot enter
you cannot enter
he cannot enter
we cannot enter
you cannot enter
they cannot enter 	I cannot be entering
you cannot be entering
he cannot be entering
we cannot be entering
you cannot be entering
they cannot be entering	I cannot have entered
you cannot have entered
he cannot have entered
we cannot have entered
you cannot have entered
they cannot have entered	I cannot have been entering
you cannot have been entering
he cannot have been entering
we cannot have been entering
you cannot have been entering
they cannot have been entering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I enter?
can you enter?
can he enter?
can we enter?
can you enter?
can they enter? 	can I be entering?
can you be entering?
can he be entering?
can we be entering?
can you be entering?
can they be entering? 	can I have entered?
can you have entered?
can he have entered?
can we have entered?
can you have entered?
can they have entered? 	can I have been entering?
can you have been entering?
can he have been entering?
can we have been entering?
can you have been entering?
can they have been entering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not enter?
can you not enter?
can he not enter?
can we not enter?
can you not enter?
can they not enter? 	can I not be entering?
can you not be entering?
can he not be entering?
can we not be entering?
can you not be entering?
can they not be entering? 	can I not have entered?
can you not have entered?
can he not have entered?
can we not have entered?
can you not have entered?
can they not have entered? 	can I not have been entering?
can you not have been entering?
can he not have been entering?
can we not have been entering?
can you not have been entering?
can they not have been entering?