must upspring
Verbe irrégulier : upspring - upsprang, upsprung- upsprung

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must upspring
you must upspring
she must upspring
we must upspring
you must upspring
they must upspring 	I must be upspringing
you must be upspringing
she must be upspringing
we must be upspringing
you must be upspringing
they must be upspringing	I must have upsprung
you must have upsprung
she must have upsprung
we must have upsprung
you must have upsprung
they must have upsprung	I must have been upspringing
you must have been upspringing
she must have been upspringing
we must have been upspringing
you must have been upspringing
they must have been upspringing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must not upspring
you must not upspring
she must not upspring
we must not upspring
you must not upspring
they must not upspring 	I must not be upspringing
you must not be upspringing
she must not be upspringing
we must not be upspringing
you must not be upspringing
they must not be upspringing	I must not have upsprung
you must not have upsprung
she must not have upsprung
we must not have upsprung
you must not have upsprung
they must not have upsprung	I must not have been upspringing
you must not have been upspringing
she must not have been upspringing
we must not have been upspringing
you must not have been upspringing
they must not have been upspringing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I upspring?
must you upspring?
must she upspring?
must we upspring?
must you upspring?
must they upspring? 	must I be upspringing?
must you be upspringing?
must she be upspringing?
must we be upspringing?
must you be upspringing?
must they be upspringing? 	must I have upsprung?
must you have upsprung?
must she have upsprung?
must we have upsprung?
must you have upsprung?
must they have upsprung? 	must I have been upspringing?
must you have been upspringing?
must she have been upspringing?
must we have been upspringing?
must you have been upspringing?
must they have been upspringing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I not upspring?
must you not upspring?
must she not upspring?
must we not upspring?
must you not upspring?
must they not upspring? 	must I not be upspringing?
must you not be upspringing?
must she not be upspringing?
must we not be upspringing?
must you not be upspringing?
must they not be upspringing? 	must I not have upsprung?
must you not have upsprung?
must she not have upsprung?
must we not have upsprung?
must you not have upsprung?
must they not have upsprung? 	must I not have been upspringing?
must you not have been upspringing?
must she not have been upspringing?
must we not have been upspringing?
must you not have been upspringing?
must they not have been upspringing?