Hi - I’m a brand new Knitter. I have crocheted for years, but am attempting a new Poncho and am lost. My pattern says “Working in St st (p 1 k 1 row), inc 1 st each and every row”. So when do I do the increase? and how? This pattern calls for 2 triangle pieces to be attached together and it appears that they attach up the middle and down the back. So with that in mind why would I be increasing if I am starting with 214 cast on stiches and increase each and every row and end up with 234 stiches?..thanks for the help.
Increase
Is the seam you’re going to be making a straight edge? After you do the increases, do you knit straight without increases for a long time? Do you have a link to the pattern? Have you had it with my questions? 
If the seam up the middle is straight, I imagine you’d increase on the outside edge to make it wider at the top. But it sound like you only increase for the first 20 rows. Is that right?
It appears to be a straight edge. It’s like fitting to triangles together with the long edges conecting up the front of the poncho and then down the back side. On row 11 it says (wrong side): P. Mark last row for hemline. Continue in St st dec’g 1 st each and every row throughout. When 18 rows above hemline beg pat 198 sts. No link to pattern as it came out of a 1974 crochet book.
I’d say you put the increases and decreases on the outside edge and work straight from there. It’s had to envision the increases and the hem and such, but I think if you just follow the pattern to the letter, you should be fine.