must clunk
Regular verb: clunk - clunked- clunked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must clunk
you must clunk
she must clunk
we must clunk
you must clunk
they must clunk 	I must be clunking
you must be clunking
she must be clunking
we must be clunking
you must be clunking
they must be clunking	I must have clunked
you must have clunked
she must have clunked
we must have clunked
you must have clunked
they must have clunked	I must have been clunking
you must have been clunking
she must have been clunking
we must have been clunking
you must have been clunking
they must have been clunking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't clunk
you mustn't clunk
she mustn't clunk
we mustn't clunk
you mustn't clunk
they mustn't clunk 	I mustn't be clunking
you mustn't be clunking
she mustn't be clunking
we mustn't be clunking
you mustn't be clunking
they mustn't be clunking	I mustn't have clunked
you mustn't have clunked
she mustn't have clunked
we mustn't have clunked
you mustn't have clunked
they mustn't have clunked	I mustn't have been clunking
you mustn't have been clunking
she mustn't have been clunking
we mustn't have been clunking
you mustn't have been clunking
they mustn't have been clunking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I clunk?
must you clunk?
must she clunk?
must we clunk?
must you clunk?
must they clunk? 	must I be clunking?
must you be clunking?
must she be clunking?
must we be clunking?
must you be clunking?
must they be clunking? 	must I have clunked?
must you have clunked?
must she have clunked?
must we have clunked?
must you have clunked?
must they have clunked? 	must I have been clunking?
must you have been clunking?
must she have been clunking?
must we have been clunking?
must you have been clunking?
must they have been clunking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I clunk?
mustn't you clunk?
mustn't she clunk?
mustn't we clunk?
mustn't you clunk?
mustn't they clunk? 	mustn't I be clunking?
mustn't you be clunking?
mustn't she be clunking?
mustn't we be clunking?
mustn't you be clunking?
mustn't they be clunking? 	mustn't I have clunked?
mustn't you have clunked?
mustn't she have clunked?
mustn't we have clunked?
mustn't you have clunked?
mustn't they have clunked? 	mustn't I have been clunking?
mustn't you have been clunking?
mustn't she have been clunking?
mustn't we have been clunking?
mustn't you have been clunking?
mustn't they have been clunking?