Regular verb: sing sing - sing singed - sing singed
Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must sing sing you must sing sing she must sing sing we must sing sing you must sing sing they must sing sing
V-ing form
I must be sing singing you must be sing singing she must be sing singing we must be sing singing you must be sing singing they must be sing singing
Perfect
I must have sing singed you must have sing singed she must have sing singed we must have sing singed you must have sing singed they must have sing singed
V-ing perfect
I must have been sing singing you must have been sing singing she must have been sing singing we must have been sing singing you must have been sing singing they must have been sing singing
Negation
Simple form
I mustn't sing sing you mustn't sing sing she mustn't sing sing we mustn't sing sing you mustn't sing sing they mustn't sing sing
V-ing form
I mustn't be sing singing you mustn't be sing singing she mustn't be sing singing we mustn't be sing singing you mustn't be sing singing they mustn't be sing singing
Perfect
I mustn't have sing singed you mustn't have sing singed she mustn't have sing singed we mustn't have sing singed you mustn't have sing singed they mustn't have sing singed
V-ing perfect
I mustn't have been sing singing you mustn't have been sing singing she mustn't have been sing singing we mustn't have been sing singing you mustn't have been sing singing they mustn't have been sing singing
Interrogative form
Simple form
must I sing sing? must you sing sing? must she sing sing? must we sing sing? must you sing sing? must they sing sing?
V-ing form
must I be sing singing? must you be sing singing? must she be sing singing? must we be sing singing? must you be sing singing? must they be sing singing?
Perfect
must I have sing singed? must you have sing singed? must she have sing singed? must we have sing singed? must you have sing singed? must they have sing singed?
V-ing perfect
must I have been sing singing? must you have been sing singing? must she have been sing singing? must we have been sing singing? must you have been sing singing? must they have been sing singing?
Interro-negative form
Simple form
mustn't I sing sing? mustn't you sing sing? mustn't she sing sing? mustn't we sing sing? mustn't you sing sing? mustn't they sing sing?
V-ing form
mustn't I be sing singing? mustn't you be sing singing? mustn't she be sing singing? mustn't we be sing singing? mustn't you be sing singing? mustn't they be sing singing?
Perfect
mustn't I have sing singed? mustn't you have sing singed? mustn't she have sing singed? mustn't we have sing singed? mustn't you have sing singed? mustn't they have sing singed?
V-ing perfect
mustn't I have been sing singing? mustn't you have been sing singing? mustn't she have been sing singing? mustn't we have been sing singing? mustn't you have been sing singing? mustn't they have been sing singing?