fix word 'substracting' to 'subtracting'
@@ -574,7 +574,7 @@ func (ng *Engine) populateSeries(ctx context.Context, q storage.Queryable, s *Ev
// We need to make sure we select the timerange selected by the subquery.
// TODO(gouthamve): cumulativeSubqueryOffset gives the sum of range and the offset
- // we can optimise it by separating out the range and offsets, and substracting the offsets
+ // we can optimise it by separating out the range and offsets, and subtracting the offsets
// from end also.
subqOffset := ng.cumulativeSubqueryOffset(path)
offsetMilliseconds := durationMilliseconds(subqOffset)
