ta.

Ultimately from bynnag (“-ever”). Initially, bynnag began preceding rather than following the word it qualified, for example, beth bynnag (“whatever”) became bynnag beth. The initial g of bynnag was velarised to produce gynnag beth, whereupon the word was reanalysed as the phrase gan nag, a southern colloquial form of gan nad, literally "since (that) not". The apparent inconsistency of negative nag being a part of a phrase with no negative connotations led its replacement with corresponding affirmative taw (“that”), so gan nag beth became gan taw beth. The initial gan was subsequently dropped and the pronunciation of taw /tau̯/ reduced to ta /ta/, as is customary, leading to such forms as ta beth (“whatever”) today.

Clipping of petai (“if it were”), itself a combination of pe (“if”) + tai (“third-person singular counterfactual impferfect subjunctive of bod (“to be”)”).