Tha = thee, the familiar form of "you". "Only thee-thou's them as thee-thou's you": family and close friends only. This is dying out. I recall my Yorkshire grandmother using it, but only intermittently.

wain't = won't nar = now

These are both on the other side of a vowel shift.

Nowt = nothing. This is a bit of dialect that's still alive, partly due to its use in the TV advertising slogan "Bread wi' Nowt Taken Out".

TV and the class system have long worked against UK regional accents and dialect.