radi+us = noun stem = noun root + stem extender radi+i = noun (word) = noun root/stem [no extender]. These suffixes are required when the stem is marked as [+Pl]. In this way, [-Pl] is never ...

All nouns in Spanish have a gender. They are either masculine or they are feminine. Every noun is either one or the other and you just have to learn them. But there are some clues. Un problema is ...