We saw by now that there are a lot of different types of nouns, with different genders and endings, so we can assume that making the plural of a noun will be somehow complicated. There isn't a simple rule on how to make plural of nouns, but I will share some basic rules so you have an idea what the plural will look like.

if nouns are taken from some foreign language, plural is usually formed by adding suffix -s

das Baby -----> die Babys baby/babys

if nouns are feminine we usually make plural by adding suffix -en (or just -n if they already have last letter e)

die Frau -----> die Frauen woman/women

die Blume -----> die Blumen flower/flowers

if nouns are masculine with ending -er, -el, -en the plural is same as singular

der Lehrer -----> die Lehrer teacher/teachers

if nouns are neutral with ending -chen, -lein the plural is also same as singular

das Mädchen -----> die Mädchen girl/girls

if nouns are masculine, we add suffix -e

Then, there are 2 cases:

we simply add -e and that's plural

we add -e, but there also needs to come to a change of vowel to its umlaut

There isn't a strict rule when this happens, so it is the best as I mentioned in one of the previous topics to learn nouns by learning both the noun, its gender and the plural.

der Ball ----> die Bälle ball/balls

der Schuh -----> die Schuhe shoe/shoes

Those were some of the main rules. When you talk to people, read in German or watch movies, you will get a sense for making plural of nouns without having to think about the rules, it will just flow naturally, so don't worry if you feel confused or scared now! 😃