Though I have followed grammar based approach for Gujarati teaching; I have purposely omitted explaining the concept of વિભક્તિ(vibhakti) and વિભક્તિ પ્રત્યય (vibhaktipratyay).
I think it is very complicated to explain and a lot confusing. Because “વિભક્તિ પ્રત્યય” table includes many suffixes which are not used in contemporary language.
I had read at one place that in modern languages there are less number of cases. And cases were replaced by prepositions in the evolution of languages. e.g. in Sanskrit and in Gujarati there are 7 cases; in German there are 4 cases while in English there are only 2 cases.
I decided to teach Gujarati in terms of English i.e. prepositions
e.g. “second vibhakti” is actually preposition “To”
Third vibhakti is preposition “by” as used in pas tense. etc.
So please refer lesson related to prepositions
https://learnmarathiwithkaushik.com/courses/prepositions-with-nouns-in-gujarati/
https://learnmarathiwithkaushik.com/courses/prepositions-with-verbs-in-gujarati/
https://learnmarathiwithkaushik.com/courses/saying-my-his-her-in-gujarati/
https://learnmarathiwithkaushik.com/courses/preposition-to-in-gujarati/
For more formal details please refer other websites through google search.