should occur
Regular verb: occur - occurred- occurred

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should occur
you should occur
he should occur
we should occur
you should occur
they should occur 	I should be occurring
you should be occurring
he should be occurring
we should be occurring
you should be occurring
they should be occurring	I should have occurred
you should have occurred
he should have occurred
we should have occurred
you should have occurred
they should have occurred	I should have been occurring
you should have been occurring
he should have been occurring
we should have been occurring
you should have been occurring
they should have been occurring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not occur
you should not occur
he should not occur
we should not occur
you should not occur
they should not occur 	I should not be occurring
you should not be occurring
he should not be occurring
we should not be occurring
you should not be occurring
they should not be occurring	I should not have occurred
you should not have occurred
he should not have occurred
we should not have occurred
you should not have occurred
they should not have occurred	I should not have been occurring
you should not have been occurring
he should not have been occurring
we should not have been occurring
you should not have been occurring
they should not have been occurring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I occur?
should you occur?
should he occur?
should we occur?
should you occur?
should they occur? 	should I be occurring?
should you be occurring?
should he be occurring?
should we be occurring?
should you be occurring?
should they be occurring? 	should I have occurred?
should you have occurred?
should he have occurred?
should we have occurred?
should you have occurred?
should they have occurred? 	should I have been occurring?
should you have been occurring?
should he have been occurring?
should we have been occurring?
should you have been occurring?
should they have been occurring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not occur?
should you not occur?
should he not occur?
should we not occur?
should you not occur?
should they not occur? 	should I not be occurring?
should you not be occurring?
should he not be occurring?
should we not be occurring?
should you not be occurring?
should they not be occurring? 	should I not have occurred?
should you not have occurred?
should he not have occurred?
should we not have occurred?
should you not have occurred?
should they not have occurred? 	should I not have been occurring?
should you not have been occurring?
should he not have been occurring?
should we not have been occurring?
should you not have been occurring?
should they not have been occurring?