-The property @code{measurePosition} contains a rational number
-indicating how much of the measure has passed at this point. Note
-that this is set to a negative number by the @code{\partial} command:
-i.e., @code{\partial 4} is internally translated to @w{@code{-4}},
-meaning @qq{there is a quarter note left in the measure.}
+The property @code{measurePosition} contains a rational number, which
+is usually positive and indicates how much of the measure has passed
+at this point. The @code{\partial @var{duration}} command sets it to
+a negative number, when it has a different meaning: it then says that
+the current (first) bar will be @emph{preceded} by a bar 0 (the partial
+bar) with a duration given by @var{duration}.