However, a small group of verbs have no argument that corresponds to this agreement morpheme.
The term bound morpheme is then used to include both affixes and clitics.
These single morpheme words are sometimes called root or base words; an example is the single morpheme words are sometimes called root or base words; an example is the single morpheme word, ' faith ' .
As such, it is a bound morpheme because its meaning only exists in conjunction with the free morpheme ' acid ' .
Even more intractable problems arise where isolating what appears to be the same morpheme leaves behind a residue of uncertain status.