must foil
Regular verb: foil - foiled- foiled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must foil
you must foil
he must foil
we must foil
you must foil
they must foil 	I must be foiling
you must be foiling
he must be foiling
we must be foiling
you must be foiling
they must be foiling	I must have foiled
you must have foiled
he must have foiled
we must have foiled
you must have foiled
they must have foiled	I must have been foiling
you must have been foiling
he must have been foiling
we must have been foiling
you must have been foiling
they must have been foiling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not foil
you must not foil
he must not foil
we must not foil
you must not foil
they must not foil 	I must not be foiling
you must not be foiling
he must not be foiling
we must not be foiling
you must not be foiling
they must not be foiling	I must not have foiled
you must not have foiled
he must not have foiled
we must not have foiled
you must not have foiled
they must not have foiled	I must not have been foiling
you must not have been foiling
he must not have been foiling
we must not have been foiling
you must not have been foiling
they must not have been foiling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I foil?
must you foil?
must he foil?
must we foil?
must you foil?
must they foil? 	must I be foiling?
must you be foiling?
must he be foiling?
must we be foiling?
must you be foiling?
must they be foiling? 	must I have foiled?
must you have foiled?
must he have foiled?
must we have foiled?
must you have foiled?
must they have foiled? 	must I have been foiling?
must you have been foiling?
must he have been foiling?
must we have been foiling?
must you have been foiling?
must they have been foiling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not foil?
must you not foil?
must he not foil?
must we not foil?
must you not foil?
must they not foil? 	must I not be foiling?
must you not be foiling?
must he not be foiling?
must we not be foiling?
must you not be foiling?
must they not be foiling? 	must I not have foiled?
must you not have foiled?
must he not have foiled?
must we not have foiled?
must you not have foiled?
must they not have foiled? 	must I not have been foiling?
must you not have been foiling?
must he not have been foiling?
must we not have been foiling?
must you not have been foiling?
must they not have been foiling?