Inc 1 stitch at each end of next row and every foll row 4 until there are 109 st???

Hello,
I’m working on a sweater and completely stumped trying to interpret the below instruction in my pattern for making the sleeves:

Inc 1 stitch at each end of next row and every foll row 4 until there are 109 star.
What is “next row”and what is foll row 4 mean?

If someone out there could dumb this down for me, that would be great!
Thanks!
Katie

Welcome!
You’ve presumably worked some number of rows before you came to this instruction. The “next row” is the one you are about to knit or purl. If you call that row, row 1 then you would inc at each end of rows 5,9,13,17,21,25,29 etc until your reach 109sts.
Remember too that you’re increasing 2 sts per increase row, one at the beginning and one at the end of the row.

Thank you very much!