How To Make M1 increase

I am working on a pair of mittens for a young man that comes through my school crossing as a reward for his good behavior this year. The pattern says to start the thumb gusset by knitting 17 stitches,pm M1,k1,M1pm knit 17.

I know that the M1 means an increase of some kind but how do I do it?

"pm M1,k1,M1pm"
Place marker, then pick up the bar between existing sts, place it on the left needle, knit through the back loop, knit one from next existing st, then pick up the bar again, place on left needle, knit through the back loop, place marker. Hope this helps…you are making stitches where one does not already exist basically. Mary

Thank you so much. Now I can finish the first mitten and then the other one. I am also going to knit him a hat to go with the mittens.

He’ll love them from his special mentor! Can’t wait to see photos!!!