Old beginner crochet problem

I am re-learning to crochet after many, many years off. It doesn't all come back automatically. At first I had a problem, and still do somethings, with the ends get shorter as a crochet, but that's getting better. No the problem I have is, it seems that my crocheting turns into a circle. I am trying to crochet straight and flat, but it just ends up turning into a big circle. I have searched and searched for what is wrong and can find nothing. I am opening for suggestions and help ya'll!! :)

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When you say your crochet is turning into a circle, do you mean that as you add rows, your piece of crochet is curving? Or do you mean you are actually crocheting in a circle?

If you begin with a foundation chain, work a row of stitches along the top of your foundation chain, turn and work a row of stitches along the top of the previous row, if your strip is curving it may be due to 1) a tight foundation chain pulling your work inward, or 2) a change in your stitch gauge where you are beginning to work tighter or more loosely causing your strip to start curving.

If you are beginning by crocheting several stitches into one, or working a short chain, joining, and then working into that circle, your piece is supposed to become a circle. However, to achieve the circle, you will need to keep adding stitches as you work more rounds.

Do you have any photos of what you are describing that you could provide a link to?

Another thing you could be doing is relaxing your tension so your stitches get bigger.
OR, you could be adding a stitch at the beginning by crocheting into the starting chain and at the end by doing the same. Be sure to count your stitches after each row. Also, make sure you are getting only one stitch per stich (pull up on the last stitch made to see what stitch yo've done it in and that there are not two (or three) stitches in the same loop. Hope this helps and good luck.

Single crochet worked in a tight gauge often curls. Washing and blocking usually solves the problem. Try a larger hook and.or loosen your tension to ease the problem.