Appendix:Old Irish delenition

Old Irish has a process by which the fricatives (and their palatalized equivalents) become stops  under certain circumstances; this process is called delenition.

Delenition generally happens when two homorganic consonants come into contact with each other. It is found in a variety of contexts, including compounding and affixation, but it is most salient for the learner in conjugation, because there are several verb endings that begin with, which becomes in a delenition environment.

The verb endings affected by delenition are:

After (and their palatalized equivalents), these endings change their initial  to, for example:
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from

Forms like these can be ambiguous with third-person plural forms using endings beginning with, which is also spelled ⟨t⟩, for example:
 * , from
 * , from

Occasionally, there is no delenition after l, e.g..

After (and their palatalized equivalents), the stem-final consonant and the ending-initial  merge into, for example:
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from
 * , from

Occasionally, however, there are forms in which the root-final consonant is retained and the ending-initial consonant simply disappears, for example, from.

A similar merger of consonants happens before third-person plural endings that start with (spelled ⟨t⟩). The voiceless consonants merge with it to, and the voiced consonants  merge with it to.
 * , from
 * , from
 * , from
 * , from

The merger of a stem-final with an ending-initial  is avoided in many verbs by the insertion of a vowel between the stem and the ending, e.g.:
 * alongside
 * (a misspelling for )
 * (a misspelling for )
 * (a misspelling for )