Yep, you are right. -in, -yn, -ian, -an: "he"/"they". -yaki, yaky, -aky: "which is/which are". Pol - field, "farmer". Polyak - which is Pol (Western Slavs).

Yep, you are right. -in, -yn, -ian, -an: "he"/"they". -yaki, yaky, -aky: "which is/which are". Pol - field, "farmer". Polyak - which is Pol (Western Slavs). Polyan - he is Pol (Eastern Slavs). Moreover, Arab: ar - horse, ab - (one) of. Arab - one of riders.