Garter stich in the round

I am doing a garter stich in the round (Pearl 1 row, knit 1 row), and in between each row it is creating a hole. Does anybody know why this happening and how I can prevent it? Any answers are much appreciated:)

I am fairly new to knitting but let me try. It sounds to me as if you are doing yarn overs. When you are doing the knit stitch the yarn should be coming from the yarn on the back side of the needle. As you switch to the purl stitch the yrn should be move between the needles and be in front of the needle.

If you are doing this then i am at a lose. Good luck

When you switch from knit to purl or purl to knit, are you bringing the yarn between the tips or over the needle?