There is only one third-declension masculine noun in modern Russian, and that word is путь, which means path or way. It declines like this:

The word is particularly often found in the phrase «по пути» “on the way”:

The word is also used in the phrase «на обратном пути» “on the way back”:

The Russian word кино is an indeclinable neuter noun. Indeclinable nouns are ones that never change their endings:

One of the meanings of кино is “cinema” or “cinematography” or “film.” Although the noun itself does not change endings, the adjective that modifies it must:

The word can also be used to mean “movie theater”:

The word can also mean a film or movie:

The most common Russian word for “to shave” — as in the daily male habit of shaving one's face — is бриться/побриться. It conjugates like this:

For instance:

The thing you shave with goes into the instrumental case without a preposition. Most of the time that will be a variation on the word бритва ‘razor’:

The most common Russian word for five is пять, which declines like this:

When пять occurs in oblique cases (oblique means a case other than nominative or accusative), it works pretty well like we would expect from a theoretical point of view; that is, it declines as we would expect and the noun it quantifies shows up in the same case in the plural:

Now here's the weird part... If пять is part of a nominative case number phrase or an accusative case number phrase, then the noun it quantifies shows up in the genitive plural:

I know, I know. You are wondering why. The answer of course is that the Russians do this for security purposes: by making the language complicated, it's easier to identify foreign spies...

Note: америкос is a mildly condescending word for Americans.

Nowadays everyone seems to have a flash drive to transfer files from one computer to another. You stick it in a USB port on your laptop and —bang!— you're in business. The most common Russian word for flash drive is флешка. Even though the third letter is е, the л is pronounced hard. It declines like this:

When you copy a file to/from a flash drive, you can use quite a few verbs, including скачивать/скачать, копировать/скопировать and скидывать/скинуть. You copy to a флешка using на + accusative:

If you copy from a флешка, you use с + genitive: