Originally used to form the second person singular of be, but can denote other present tense forms, such as: are, am, is
*1875 , Mark Lemon, Henry Mayhew, Tom Taylor, Punch :
*1904 , Henry Branch, Cotswold and vale :
- Thee bist rayther too much a feelosofer, I be afeard, for me.
- Lookee, thee bist' purty, my love; lookee, thee ' bist purty: thee hast dove's eyes betwix thy locks; thy locks be like a flock o' ship fur thickedness.
:: Where are you going?
- Where bist goin'.
:: I am going home
- I bist goin' 'ome.
:: How are you?
- How bist ?