Fixed wording of the comment.

@@ -1035,13 +1035,13 @@ util_wcard_match (const char *string, const char *pattern, const char *delim)
 
 /* Return the uindvalidity of a mailbox.
    When a mailbox is selected, whose first message does not keep X-UIDVALIDITY
-   value, the uidvalidity is computed based on the return of time(). Now,
+   value, the uidvalidity is computed basing on the return of time(). Now,
    if we call "EXAMINE mailbox" or "STATUS mailbox (UIDVALIDITY)" the same
    mailbox is opened second time and the uidvalidity recalculated. Thus each
    subsequent call to EXAMINE or STATUS upon an already selected mailbox
-   will return different uidvalidity value. To avoid this, util_uidvalidity()
+   will return a different uidvalidity value. To avoid this, util_uidvalidity()
    first sees if it is asked to operate upon an already opened mailbox
-   and if so, returns previously computed value. */
+   and if so, returns the previously computed value. */
 int
 util_uidvalidity (mailbox_t smbox, unsigned long *uidvp)
 {