I must travel you must travel she must travel we must travel you must travel they must travel
V-ing form
I must be travelling you must be travelling she must be travelling we must be travelling you must be travelling they must be travelling
Perfect
I must have travelled you must have travelled she must have travelled we must have travelled you must have travelled they must have travelled
V-ing perfect
I must have been travelling you must have been travelling she must have been travelling we must have been travelling you must have been travelling they must have been travelling
Negation
Simple form
I mustn't travel you mustn't travel she mustn't travel we mustn't travel you mustn't travel they mustn't travel
V-ing form
I mustn't be travelling you mustn't be travelling she mustn't be travelling we mustn't be travelling you mustn't be travelling they mustn't be travelling
Perfect
I mustn't have travelled you mustn't have travelled she mustn't have travelled we mustn't have travelled you mustn't have travelled they mustn't have travelled
V-ing perfect
I mustn't have been travelling you mustn't have been travelling she mustn't have been travelling we mustn't have been travelling you mustn't have been travelling they mustn't have been travelling
Interrogative form
Simple form
must I travel? must you travel? must she travel? must we travel? must you travel? must they travel?
V-ing form
must I be travelling? must you be travelling? must she be travelling? must we be travelling? must you be travelling? must they be travelling?
Perfect
must I have travelled? must you have travelled? must she have travelled? must we have travelled? must you have travelled? must they have travelled?
V-ing perfect
must I have been travelling? must you have been travelling? must she have been travelling? must we have been travelling? must you have been travelling? must they have been travelling?
Interro-negative form
Simple form
mustn't I travel? mustn't you travel? mustn't she travel? mustn't we travel? mustn't you travel? mustn't they travel?
V-ing form
mustn't I be travelling? mustn't you be travelling? mustn't she be travelling? mustn't we be travelling? mustn't you be travelling? mustn't they be travelling?
Perfect
mustn't I have travelled? mustn't you have travelled? mustn't she have travelled? mustn't we have travelled? mustn't you have travelled? mustn't they have travelled?
V-ing perfect
mustn't I have been travelling? mustn't you have been travelling? mustn't she have been travelling? mustn't we have been travelling? mustn't you have been travelling? mustn't they have been travelling?