Russian slang: composing loanwords

In Russian is quite common to use foreign (especially English) words. These loanwords are usually modified by language in a certain way and in a while become new slang words. Russian could understand these words easily, but for foreigners these words become a headache. Every Russian knows how it works.

In Russian almost every word has preposition, root, and ending. Preposition gives a direction, root is what the word is, ending is about single-plural, cases, imperative etc.
Then let’s take “Log in” or “Зайти” in Russian. By the way, “Зайти” is not a perfect translation of “Log in” but in a single word it could be closest.

Look how the word Зайти is composed:
Зайти = За (direction – in) + йти (derivative from идти, means to go)
Now you see, “Зайти” means “to go in”, not “to log in”

Then let’s compose a loanword. All we need to do is to change the root.
За + login
Now we have the base, all we need in now is transliterate login into Russian and add typical ending:
За + логин + иться = Залогиниться

Why did we pick such an ending? Just because we treat the root according to rules of Russian language. Ending is equal to similar words:
• Залогиниться
• Провиниться
Then, you’ll ask me where is the lexical stress in this new word? Exactly where it was in English word: залогИниться

Hope this explains a lot. =)