Notmuch has a test suite with fairly good coverage. At the very least, `make
test` must pass after your changes. Therefore you must amend the tests if you
-make functional changes that have existing test coverage. Preferrably, you
+make functional changes that have existing test coverage. Preferably, you
should add new tests for any new functionality, and it helps in getting your
changes accepted.
## Report bugs
-Send bug reports to the Notmuch mailing list. Preferrably prefix the
+Send bug reports to the Notmuch mailing list. Preferably prefix the
subject line with "BUG:" or similar. Tag the message as a bug in
[nmbug](http://notmuchmail.org/nmbug/).