Mes In Plural Form

Question

I know Spanish words that end with an "s" or an "x" you do not need to put "es" at the end of them to make them plural, so why when mes is plural it has an "es" at the end of it?

Answer 1

That rule only applies when the last syllable is unstressed so only the article changes to plural. The object stays the same. So in general if a noun ends in a vowel, add -s. If a noun ends in a consonant, add -es.

So, un mes y dos meses.