I must fiddle you must fiddle she must fiddle we must fiddle you must fiddle they must fiddle
V-ing form
I must be fiddling you must be fiddling she must be fiddling we must be fiddling you must be fiddling they must be fiddling
Perfect
I must have fiddled you must have fiddled she must have fiddled we must have fiddled you must have fiddled they must have fiddled
V-ing perfect
I must have been fiddling you must have been fiddling she must have been fiddling we must have been fiddling you must have been fiddling they must have been fiddling
Negation
Simple form
I must not fiddle you must not fiddle she must not fiddle we must not fiddle you must not fiddle they must not fiddle
V-ing form
I must not be fiddling you must not be fiddling she must not be fiddling we must not be fiddling you must not be fiddling they must not be fiddling
Perfect
I must not have fiddled you must not have fiddled she must not have fiddled we must not have fiddled you must not have fiddled they must not have fiddled
V-ing perfect
I must not have been fiddling you must not have been fiddling she must not have been fiddling we must not have been fiddling you must not have been fiddling they must not have been fiddling
Interrogative form
Simple form
must I fiddle? must you fiddle? must she fiddle? must we fiddle? must you fiddle? must they fiddle?
V-ing form
must I be fiddling? must you be fiddling? must she be fiddling? must we be fiddling? must you be fiddling? must they be fiddling?
Perfect
must I have fiddled? must you have fiddled? must she have fiddled? must we have fiddled? must you have fiddled? must they have fiddled?
V-ing perfect
must I have been fiddling? must you have been fiddling? must she have been fiddling? must we have been fiddling? must you have been fiddling? must they have been fiddling?
Interro-negative form
Simple form
must I not fiddle? must you not fiddle? must she not fiddle? must we not fiddle? must you not fiddle? must they not fiddle?
V-ing form
must I not be fiddling? must you not be fiddling? must she not be fiddling? must we not be fiddling? must you not be fiddling? must they not be fiddling?
Perfect
must I not have fiddled? must you not have fiddled? must she not have fiddled? must we not have fiddled? must you not have fiddled? must they not have fiddled?
V-ing perfect
must I not have been fiddling? must you not have been fiddling? must she not have been fiddling? must we not have been fiddling? must you not have been fiddling? must they not have been fiddling?