I must lay you must lay she must lay we must lay you must lay they must lay
V-ing form
I must be laying you must be laying she must be laying we must be laying you must be laying they must be laying
Perfect
I must have laid you must have laid she must have laid we must have laid you must have laid they must have laid
V-ing perfect
I must have been laying you must have been laying she must have been laying we must have been laying you must have been laying they must have been laying
Negation
Simple form
I must not lay you must not lay she must not lay we must not lay you must not lay they must not lay
V-ing form
I must not be laying you must not be laying she must not be laying we must not be laying you must not be laying they must not be laying
Perfect
I must not have laid you must not have laid she must not have laid we must not have laid you must not have laid they must not have laid
V-ing perfect
I must not have been laying you must not have been laying she must not have been laying we must not have been laying you must not have been laying they must not have been laying
Interrogative form
Simple form
must I lay? must you lay? must she lay? must we lay? must you lay? must they lay?
V-ing form
must I be laying? must you be laying? must she be laying? must we be laying? must you be laying? must they be laying?
Perfect
must I have laid? must you have laid? must she have laid? must we have laid? must you have laid? must they have laid?
V-ing perfect
must I have been laying? must you have been laying? must she have been laying? must we have been laying? must you have been laying? must they have been laying?
Interro-negative form
Simple form
must I not lay? must you not lay? must she not lay? must we not lay? must you not lay? must they not lay?
V-ing form
must I not be laying? must you not be laying? must she not be laying? must we not be laying? must you not be laying? must they not be laying?
Perfect
must I not have laid? must you not have laid? must she not have laid? must we not have laid? must you not have laid? must they not have laid?
V-ing perfect
must I not have been laying? must you not have been laying? must she not have been laying? must we not have been laying? must you not have been laying? must they not have been laying?