I must foul you must foul he must foul we must foul you must foul they must foul
V-ing form
I must be fouling you must be fouling he must be fouling we must be fouling you must be fouling they must be fouling
Perfect
I must have fouled you must have fouled he must have fouled we must have fouled you must have fouled they must have fouled
V-ing perfect
I must have been fouling you must have been fouling he must have been fouling we must have been fouling you must have been fouling they must have been fouling
Negation
Simple form
I mustn't foul you mustn't foul he mustn't foul we mustn't foul you mustn't foul they mustn't foul
V-ing form
I mustn't be fouling you mustn't be fouling he mustn't be fouling we mustn't be fouling you mustn't be fouling they mustn't be fouling
Perfect
I mustn't have fouled you mustn't have fouled he mustn't have fouled we mustn't have fouled you mustn't have fouled they mustn't have fouled
V-ing perfect
I mustn't have been fouling you mustn't have been fouling he mustn't have been fouling we mustn't have been fouling you mustn't have been fouling they mustn't have been fouling
Interrogative form
Simple form
must I foul? must you foul? must he foul? must we foul? must you foul? must they foul?
V-ing form
must I be fouling? must you be fouling? must he be fouling? must we be fouling? must you be fouling? must they be fouling?
Perfect
must I have fouled? must you have fouled? must he have fouled? must we have fouled? must you have fouled? must they have fouled?
V-ing perfect
must I have been fouling? must you have been fouling? must he have been fouling? must we have been fouling? must you have been fouling? must they have been fouling?
Interro-negative form
Simple form
mustn't I foul? mustn't you foul? mustn't he foul? mustn't we foul? mustn't you foul? mustn't they foul?
V-ing form
mustn't I be fouling? mustn't you be fouling? mustn't he be fouling? mustn't we be fouling? mustn't you be fouling? mustn't they be fouling?
Perfect
mustn't I have fouled? mustn't you have fouled? mustn't he have fouled? mustn't we have fouled? mustn't you have fouled? mustn't they have fouled?
V-ing perfect
mustn't I have been fouling? mustn't you have been fouling? mustn't he have been fouling? mustn't we have been fouling? mustn't you have been fouling? mustn't they have been fouling?