-tid

Etymology
From, from , from (stem ; compare 🇨🇬), from  (whence 🇨🇬 and 🇨🇬).

Usage notes
/tɪd/ and /dɪd/ are variants of the same suffix. /tɪd/ (phonetically [tʰɪd]) is always spelt whereas /dɪd/ would, in theory, be represented by  after an unvoiced fricative (phonetically [tɪd]) and by  after other voiced sounds (phonetically [dɪd]). /dɪd/, however, does not at present occur in any Welsh words after an unvoiced fricative.

Suffix

 * , -ness, -ment

Usage notes
-did causes i-affection of internal vowels.