My Knit/Purl pattern is messed up?!

[carrrrrrrrrrie]

Okay so im new to purl but I know how to do it. I have tried just alternating rows of knit/purl (Row 1: Knit , Row 2: Purl, Repeat) but half way through the project the stitches start reversing and it looks as if each row goes K, P, K, P, P, K, P, K, and it looks completely off. EVERYTIME I try to purl, it happens. And I am making sure I follow the K, P, K, P pattern. Help please?????

[salmonmac]

You're probably either knitting 2 tows or purling 2 rows and that's what is throwing your pattern off. When you start a new row, look at the stitches on the side facing you. If they look like Vs, it's a knit row and if they look like a dash or a loop, it's a purl row. Some of the advice and pictures here may help.
Welcome to Knitting Help!

[Antares]

Did you put your work down in the middle of a row and then start knitting the opposite way? That can happen sometimes, too. It's a good idea to always finish a row before you put it down.

P.S. I'd hate to have to type in your username every time I came here! Now how many r's was that?

[Becky Morgan]

Also, decide which side of the work you want to show the knit side. Mark that side with something--a safety pin, a bit of yarn that doesn't match, a stick pin, whatever. That way when you put down your work you'll know what to do when you pick it up.

[Rorshach]

It would seem to me that if you're setting the project down and then coming back to it, this type of thing can happen. One trick i use when trying to remember which type I'm working with, (knit or purl) is I look at the last row that was done. Since you're working in stockinette, the purl side will be all bumps, and the knit side will be smooth, and look like v's.