However, a small group of verbs have no argument that corresponds to this agreement morpheme.
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 ' .
The term bound morpheme is then used to include both affixes and clitics.
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.