why is "Jij eet soms vlees" is not accepted. As i understood both should be interchangeable in use.
Why is it "Je eet soms vlees" and "Je ziet mij soms?" What changes the placement of "soms?"
it's what this lesson is about. In short it has to do with indefinite (vlees) and definite (mij) objects. When an indefinite object is used, the adverb is placed behind the verb. For more info: https://www.duolingo.com/skill/dn/word-order-1/tips-and-notes