The eternal question for the would-be yarn-crafter. I daresay there’s more than one point of view (there always is), but as someone who’s learned to do both, I have to come down unequivocally on the side of crochet: learn to crochet first!
First, crochet is much easier to do. You have one implement, a single hook, as opposed to two needles. The hook will pretty reliably pull yarn through even for a beginner, while pulling a loop through another loop with the tip of a knitting needle takes practice. (Images borrowed from Heart Hook Home and Pom Pom Quarterly.)
Secondly, crochet is more difficult to screw up. At any given time, the only open stitch you have to worry about is the one you’re currently working; all the other stitches are closed off. This means that in crochet, it’s impossible to “drop a stitch,” which can happen to the most experienced knitter. In knitting, all your active stitches (the whole row you’re working on) are held on the needles while you work, and if you drop one (if it literally falls off the end of your needle), it can start to unravel, all the way down to the first row. In crochet, it’s also much easier to unravel and do part of the work over; you just pull on the yarn, and your most recent stitches will unravel leaving the earlier ones untouched and unimperiled, whereas in knitting, if you want to backtrack, you have to either painstakingly undo each stitch while keeping the loop from the previous row on one of the needles, or be very bold and PULL THE NEEDLES OUT, unravel the work back to the point before your mistake, and then very carefully thread the stitches back onto the needles. (Without dropping any.) (I usually do this if I need to unravel more than one row, but I’m known for being crazy in this respect.)
Third, crochet will give you an excellent grounding in what to do with your left hand (or right, if you’re a leftie), which is exactly the same for knitting as it is for crochet. With your non-dominant hand, you hold the working yarn twisted around a couple of your fingers to maintain the all-important tension. You can’t just knit or crochet from loose yarn without holding onto it somehow to make it taut, and to hold the working yarn in place where your hook or needle can reach it. If you could, your work would be loose and sloppy, which is a look, but not what you want for most things. So it’s important, when learning either knitting or crochet, to learn how to hold an even tension, not too loose, not too tight, and always pretty much the same, so that your stitches will be the same as each other. You can learn this just as well with crochet, which is easy, and then learn the two-needle mechanics of knitting later.
Fourth, crochet is considerably easier to learn, and not just because, as I mentioned before, it’s easier to do. I learned to knit about six or eight times before it actually took. I started going to a knitting group, learned to cast on and knit and purl, went home, didn’t practice, and came back the next week only to find I’d completely forgotten it.
Repeat for three weeks.
I’m not the only person who’s had this experience. Every person I’ve taught to knit has done the same. Ask anyone who’s learned to knit as an adult: if you don’t practice EVERY DAY until it’s solidly engrained in your muscle memory, it will completely fall out of your head inside a week. Why? My theory is that knitting is just deeply counter-intuitive. It’s not like anything else you have ever learned to do: making a fabric by pulling loop after loop through another loop, row by row, back and forth and having to turn your work, and going right to left?
My mother-in-law, on the other hand, taught me to crochet in half an hour, and I was off like a rocket.
You might be wondering at this point whether you should even bother learning to knit. If knitting is so difficult, and weird, why try it?
Knitting is difficult to learn, but deeply logical in its own weird way. There are only two stitches (which can be combined in many ways to create divers effects), and knitting behaves very predictably. Just keep going back and forth, you make a rectangle. Make four increases at the right places, you make a triangle. Knit round and around a circular needle, you make a tube! Not to mention, knitting is quite soothing to do once you’re in practice. You can learn a basic pattern, like seed stitch or ribbing, and do that mindlessly in front of the television, just to keep your hands busy, and still do it right. (I thought I would find the repetition maddening, but it’s really therapeutic.)
Also, knitting and crochet are good for different things. Crochet creates a more rigid, solid fabric, with very little stretch, while knitting creates a pliable, drapey, stretchy fabric, even if the yarn you’re using is not stretchy at all. This makes crochet excellent for anything you want to be stiff and hold its shape, like amigurumi (crochet animals and mini models and so on), or a bag, or certain kinds of hats. Knitting is better for anything you want to be soft and draping, like shawls and other garments, or stretchy for hats and gloves. Crochet is also better for making round things or anything with fine details, like a flower for a hat, or a Christmas ornament, or stuffed animals, while knitting is great for making things with straight lines and big geometric panels. And cables. Knitting is infinitely better for making anything with cables. (I finally came to terms with knitting by making a cabled tea-cozy. I ♥ cables.)
One last note if you’re planning to take up either one: get someone to teach you. Once you’re comfortable with knitting or crochet, it’s really easy to pick up new tricks from YouTube tutorials (or even books!), but when you’re getting started, you really need someone sitting there to show you exactly how to hold the yarn, and tell you what you’re doing wrong as you make your first few stitches. Invest in an hour or two with someone who really knows their stuff, and you’ll save yourself weeks of aggravation.
I hope this has helped to clear up some of the differences between knitting and crochet. Any questions are welcome in the comments!