Confused about YF

I want to knit the Fern Lace stitch pattern from the Lace and Eyelets Harmony Guide. I know that yf means yarn to the front/forward, but how to knit the next stitch with the yarn in front? Here is the part giving me trouble:

k3, yf, k2, sl1, k1, psso, k2tog, k2, yf, k1

I am assuming that in doing a YF I am making a yarn over? Otherwise I can’t figure out how to make a knit stitch with yarn in front for the life of me.

u r right
YF makes a yarnover
or it can makeslip stitches pucker, or show

When yf is between knit sts as in your pattern, it’s the same as a YO.