Help with sleeve decreases

The instructions are for 4, 6, 8 and 10

Knit the next 2 rows straight and begin to decrease as follows :
Every 2 rows : // // 2 times //
All 4 and 2 rows : 5 times 5 times // 3 times
Every 4 rows : 7 times 8 times 16 times 14 times

What does "All 4 and 2 rows " mean?

Welcome!
What pattern are you working on? When you say, “The instructions are for 4,6,8 and 10” do you mean sizes? If so, which size are you making?

The pattern is “Les Wouimardis” purchased off Ravelry. I am making the size 4. I have knitted the two rows straight and understand that “Every 2 rows” does not apply to size 4. I do not understand how to apply “all 4 and 2 rows”. Am I to decrease every 4th and 2nd row? Should I count 4 rows, decreasing on the 4th, count 2, decreasing on the 2nd?

Alternating every 4th and 2nd row would be my guess too. Since it’s a paid pattern, I recommend contacting the designer just to make sure. It’s a translation and something is just a little off.
Les Wouimardis are on Ravelry with several patterns in French and in English.

Thanks for your help!