Cant understand when i can write in the and of the word - ю/ий/ь/мо/all the option. Someone can explane that for me. Need also to add course about that on the begining. Thanks
Do you mean the ending of an adjective?
-ю -> noun (with a certain consonant at the end), feminine, Accusative (цибулю)
-ий -> adjective, masculine, Nominative (маленький)
-ь -> noun, masculine/feminine, Nominative (біль/сіль)
-мо -> verb, 3rd person plural (we), present tense (читаємо)
These are the things I thought of after reading your question. I'm not sure I understood it.