Ladies, please explain 'yarn' to me!

[Chulita]

Ok, just venturing forth into the world of crochet and knitting and am very confused.
What's Double Knitting wool?
Can I use 3-ply yarn if the pattern says 4-ply?
What will happen if I do?
How the heck do you actually do a granny square in crochet?

You'll be needing JackBauer. 'He' loves a spot of crochet...

Oi Jack!

Particularly if you are just starting to knit, it is essential to use the yarn specified in the pattern, or at least one that knits to the same tension. If you use a different yarn you will end up with a smaller or larger whatever-it-is-you're-knitting. So you can't substitute 3 ply for 4 ply wool. Also, boring though it is, please do knit a tension square as recommended in the pattern and - it will save disappointment later!

Chulita - Basically they are all different thicknesses. Can you get to a wool shop and have a good look round there. it will all become so much clearer and I'm sure there will be someone only too pleased to help and explain things. Wish I could come with you as they are such lovely places...... the colours, textures...

For the granny square there are tutorials on the web to show how to do it. Maybe someone can give a link to one for you.

DK is thicker than 4-ply, which is thicker than 3-ply. Basically 'ply' means a single thread, so 3 has 3 of them twisted together and 4 has four of them twisted together.

If you are doing anything by hand as a beginner, I would suggest using DK or 4-ply. 3-ply has too many stitches and too many rows and can be demoralising. Even better, go for 'chunky', which is even thicker than DK.

Basically, the thicker yarn, the fewer stitches and rows you need, so the quicker you can complete your garment.

A granny square in crochet is blocks of three trebles and one chain. The subsequent row fits the trebles into the gap made by the chain. A granny square is very quick to crochet because trebles are very tall, and there is quite a lot of 'hole' in it, so that is something you don't have to fill.

Also, not all 'yarn' is wool. In fact, if you are just beginning to knit and crochet you are better off with a ball of DoubleKnit acrylic which you can get in many places, 100gram ball for around a £1.00
You can google 'granny square crochet'

And join Ravelry (ravelry.com) You need to ask for an invitation but it comes through quite quickly and there is a lot of information, both for advanced and beginning knitters.

Sorry, I am reading these, I just had a pounding headache yesterday and tried to avoid screens!
I think I've been going wrong by doing an English double because I was following an American pattern - just realised the names are different.
I'll have a look at Ravelry, thank you And I just found some DK acrylic so I'll see what I can make.
Thanks for your help!