New to knitting, and I need help

[Lucy130487]

Hi everyone,
I've just started knitting and I can knit and purl, however when I knit 1, purl 1, my stitches increase.
It's almost like instead of just one piece of yarn per stitch, they have a loop creating to two pieces of yarn per stitch.
What am I doing wrong?

[salmonmac]

Hi and welcome!
You may be taking the working yarn over the right needle when you change between knits and purls. Be sure to bring the working yarn between the two needles when you change stitches.