Inflections formed by Changes of Initial Consonants.
The changes in Welsh, classified according to the relationship of the sounds are—
1. From the sharp lenes to the corresponding flats; as p to b, t to d, c to g. The changes in Irish are the same.
2. From the flat lenes to their corresponding so-called aspirates; as b to v, d to ð. This is the change in Welsh. In Irish we have the same, but only as far as b is concerned; the aspirate of d (ð) being wanting in that language. In neither Welsh nor Irish occurs the true aspirate of g. In neither Welsh nor Irish occurs the true aspirate of c; which, being wanting, is replaced by the sound of the ch in the German auch, here spelt ç.
Now the Welsh grammarians deal with the changes from sharp to flat, and from lene to aspirate, alike; since, in respect to the grammar of their language, they are enabled to state that they take place under the same circumstances.
Taken collectively they are called light: and words wherein p is changed to b, and those wherein b is changed to v, are equally said to assume the light sound. This the Welsh express in spelling, and write ben for pen, and vraint for braint, &c. In Irish the arrangement is different. When a so-called aspirate is substituted for a lene, the word is said to take an aspiration, and bheul is written beul. If, however, the sharp be made flat, the original sound is said to be eclipsed. In spelling, however, it is preserved; so that teine, with the t changed, is written dteine, and pronounced deine. With this view we can now ask how far the change from p to b, t to d, c to g, b to v, c to ç, takes place in Irish and Welsh under similar circumstances.
In Welsh—after all verbs, except those of the infinitive mood; as caravi gaer (for caer)=I love a fort.
In Irish—after all verbs, provided that the substantive be masculine; as ta me ag gearrad çrainn=I am cutting (at to cut) a tree. Here çrainn comes from crainn. This change in Irish extends only to the change from lene to aspirate.
In Welsh—after the possessive pronouns thy, thine, his, its, mine (but not my); as dy vâr (for bâr)=thy wrath; ei vraint (from braint)=his privilege. N. B. Although the same word (ei) means her, his, and its, it induces the light change only when it is either masculine or neuter.
In Irish—after the possessive pronouns my, thy, and his. Here the change is of the first sort only, or an aspiration; as mo vàs (bàs)=my death; do ços (cos)=thy foot; çeann (ceann)=his head. N. B. Although the same word (a) means her, his, and its, it induces the aspirate only when it is either masculine or neuter.