This paper offers an analysis of tu(pas) in Quebec French in terms of featu
re composition. It is proposed that the features of tu are checked both at
PF and LF. It is argued that tu represents a PF reflex of an emphatic stres
s on the last syllable of the prosodic unit Vfinite+tu and it is a LF refle
x of a reinforcer in the internal domain of TP for certain types of mood-fo
rce expressions. However, it is not an inherent illocutionary Force marker.
It is illustrated how tu pas creates an aspectual effect in discourse and
is connected to predicates with a built-in terminal point. Even though tu p
as must sometimes appear obligatorily together in the proposition, the two
forms bring a different contribution to the meaning of the sentence. It is
argued that tu is a Force operator identified in the CP domain at LF and pa
s is a negative marker which is interpretated with a reverse positive polar
ity when it scopes over tu.