I must backtrack you must backtrack she must backtrack we must backtrack you must backtrack they must backtrack
V-ing form
I must be backtracking you must be backtracking she must be backtracking we must be backtracking you must be backtracking they must be backtracking
Perfect
I must have backtracked you must have backtracked she must have backtracked we must have backtracked you must have backtracked they must have backtracked
V-ing perfect
I must have been backtracking you must have been backtracking she must have been backtracking we must have been backtracking you must have been backtracking they must have been backtracking
Negation
Simple form
I must not backtrack you must not backtrack she must not backtrack we must not backtrack you must not backtrack they must not backtrack
V-ing form
I must not be backtracking you must not be backtracking she must not be backtracking we must not be backtracking you must not be backtracking they must not be backtracking
Perfect
I must not have backtracked you must not have backtracked she must not have backtracked we must not have backtracked you must not have backtracked they must not have backtracked
V-ing perfect
I must not have been backtracking you must not have been backtracking she must not have been backtracking we must not have been backtracking you must not have been backtracking they must not have been backtracking
Interrogative form
Simple form
must I backtrack? must you backtrack? must she backtrack? must we backtrack? must you backtrack? must they backtrack?
V-ing form
must I be backtracking? must you be backtracking? must she be backtracking? must we be backtracking? must you be backtracking? must they be backtracking?
Perfect
must I have backtracked? must you have backtracked? must she have backtracked? must we have backtracked? must you have backtracked? must they have backtracked?
V-ing perfect
must I have been backtracking? must you have been backtracking? must she have been backtracking? must we have been backtracking? must you have been backtracking? must they have been backtracking?
Interro-negative form
Simple form
must I not backtrack? must you not backtrack? must she not backtrack? must we not backtrack? must you not backtrack? must they not backtrack?
V-ing form
must I not be backtracking? must you not be backtracking? must she not be backtracking? must we not be backtracking? must you not be backtracking? must they not be backtracking?
Perfect
must I not have backtracked? must you not have backtracked? must she not have backtracked? must we not have backtracked? must you not have backtracked? must they not have backtracked?
V-ing perfect
must I not have been backtracking? must you not have been backtracking? must she not have been backtracking? must we not have been backtracking? must you not have been backtracking? must they not have been backtracking?