In East Slavic languages, which are basically of singular–plural system, the singular suffix -ин- ('-in-', Russian', -yn-', Ukrainian), resp. '-ін- '('-in-', Belarusian) performs the singulative function for collective nouns.[2] Russian: gorokh (peas in mass) vs. goroshina (a single pea). Ukrainian: пісок/pisok (sand) vs. піщина/pischyna (grain of sand).[2] Belarusian: бульба (potatoes in mass, e.g. as a crop or as a species) vs. бульбіна (one potato tuber). Notice the affix '-a' in all these examples, which indicates the feminine form.