How to check the word "bitterness"?
The word "bitterness" is the noun of the third declension and the feminine gender in which we distinguish the zero ending: Bitterness-Bitterness-Bitterness.
The stress in it falls on the first syllable:
The root of the word is the morpheme GORCHE-: Gruchit-Gorechavka-Gorky.
Note that in this root there is an unstressed E, and the word itself can be mistakenly written as "hot."
Note that in the word "bitter" or "Gorky", this vowel turns out to be fluent, and the vowel can not be runaway.
The soft sign in this word indicates its belonging to the female genus.
In the word "GORCHE" it is necessary to check the unstressed vowel E, for this we find test words in which the given vowel will be a shock: bitter, bitter, bitter. The verification is impossible, and therefore the writing of E is remembered.
Since this is a feminine noun 3 declension, at the end of the word we write a soft sign: a furnace, a trifle, a youth.