English verb conjugation
MUST BUCKLE

Regular verb: buckle - buckled - buckled

Affirmation

Simple form	V-ing form
I must buckle you must buckle she must buckle we must buckle you must buckle they must buckle	I must be buckling you must be buckling she must be buckling we must be buckling you must be buckling they must be buckling
Perfect	V-ing perfect
I must have buckled you must have buckled she must have buckled we must have buckled you must have buckled they must have buckled	I must have been buckling you must have been buckling she must have been buckling we must have been buckling you must have been buckling they must have been buckling

Negation

Simple form	V-ing form
I mustn't buckle you mustn't buckle she mustn't buckle we mustn't buckle you mustn't buckle they mustn't buckle	I mustn't be buckling you mustn't be buckling she mustn't be buckling we mustn't be buckling you mustn't be buckling they mustn't be buckling
Perfect	V-ing perfect
I mustn't have buckled you mustn't have buckled she mustn't have buckled we mustn't have buckled you mustn't have buckled they mustn't have buckled	I mustn't have been buckling you mustn't have been buckling she mustn't have been buckling we mustn't have been buckling you mustn't have been buckling they mustn't have been buckling

Interrogative form

Simple form	V-ing form
must I buckle? must you buckle? must she buckle? must we buckle? must you buckle? must they buckle?	must I be buckling? must you be buckling? must she be buckling? must we be buckling? must you be buckling? must they be buckling?
Perfect	V-ing perfect
must I have buckled? must you have buckled? must she have buckled? must we have buckled? must you have buckled? must they have buckled?	must I have been buckling? must you have been buckling? must she have been buckling? must we have been buckling? must you have been buckling? must they have been buckling?

Interro-negative form

Simple form	V-ing form
mustn't I buckle? mustn't you buckle? mustn't she buckle? mustn't we buckle? mustn't you buckle? mustn't they buckle?	mustn't I be buckling? mustn't you be buckling? mustn't she be buckling? mustn't we be buckling? mustn't you be buckling? mustn't they be buckling?
Perfect	V-ing perfect
mustn't I have buckled? mustn't you have buckled? mustn't she have buckled? mustn't we have buckled? mustn't you have buckled? mustn't they have buckled?	mustn't I have been buckling? mustn't you have been buckling? mustn't she have been buckling? mustn't we have been buckling? mustn't you have been buckling? mustn't they have been buckling?