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