Thanks to the people who helped me write it out and tested it for clarity for me.
I am planning on putting some pictures of an in-progress rectangle granny, since I know some crocheters do better if they have a picture for comparison... I'll try to get that done in the next few days. Until then, try your best with just the text of the pattern.
And, if any thing in the pattern needs to be clarified, please tell me and I'll see if I can figure it out. Just remember, this was my first ever attempt at writing out a pattern.
Rectangular Granny Afghan
Special stitches: (corner shells are 3 dc, ch-1, 3 dc)
Hint: when fastening off leave a long tail to be worked in later so the stitches won’t come apart.
Dc in 4th ch from hook and next 2 chs, ch1 *sk 1 ch, dc in next 3chs, ch 1* repeat from * to * across (9 more times) ending with 1 dc in last ch. fasten off leaving a long tail to weave in
Attach new yarn in last ch-1 sp before the last dc. Ch 3, 2 dc, ch-1 in same sp, 3 dc, ch-1, 3 dc, ch-1 inside dc loop, working on other side of starting ch (3 dc, ch-1 in each sp across) until ch 4 loop (3dc, ch-1, 4 times in loop), (3dc, ch-1 in each sp across) joining with sl st in first dc.
Round 3: Attach red in first ch-1 sp of row 2 (ch 3, 2 dc, ch-1, 3dc ch-1 in same sp for corner, 3 dc, ch-1 in next sp, (3 dc, ch-1, 3 dc, ch-1 in next sp for corner) 3 dc, ch-1 in each sp across joining in ch 3.
Round 4: continue in pattern until size desired.
For more than one row of same color after joining sl st to the first ch sp and work in pattern.