Instrumental singular for means and company

You already know how to say where something is and to whom you give it. Now two more everyday things: what you do something with, and who you are with. English uses the little words by and with for both. Serbian uses one new form of the noun — and a preposition only for one of the two jobs.

The new form is called the instrumental. Look at what happens to the end of the word: autobus (a bus) becomes Idem autobusom — "I go by bus".

The endings

The instrumental singular ending is -om almost everywhere. After a soft consonant it is -em instead, purely because that is easier to say.

So for feminine nouns you swap -a for -om; for neuter nouns you swap -o or -e for -om or -em; for masculine nouns you simply add the ending to the whole word.

Job one: the means — no preposition

When the noun is the tool, the vehicle, the thing you do it by or with, the instrumental stands alone. Nothing goes in front of it.

• Idem autobusom. — I go by bus.
• Supu jedem kašikom. — I eat soup with a spoon.
• Ideš li na posao tramvajem? — Do you go to work by tram?
• Račun plaćam karticom. — I pay the bill by card.

Job two: company — with s or sa

When the noun is a companion — a person you are with, or something served together with your food — you put s or sa in front, and the noun still takes the instrumental ending.

• Idem u restoran sa bratom. — I am going to the restaurant with my brother.
• Pijem kafu sa mlekom. — I drink coffee with milk.
• Sendvič sa mesom, molim vas. — A sandwich with meat, please.

Ordering: what you can ask for it with

This is the lesson's most useful list. Take the word off the menu, put the ending on, and your order is finished.

s or sa?

They are the same word. Use sa when the next word begins with s, š, z, ž — sa sestrom, sa šećerom, sa ženom — because s sestrom is unsayable. Everywhere else s is enough: s bratom, s mlekom. In everyday speech people say sa almost everywhere, and that is never wrong, so if in doubt say sa.

With me the form is fixed and always takes sa: sa mnom — "with me". Learn it as one chunk.

The trap

Both jobs use the same ending, so the only thing that separates them is the preposition — and English gives you no help, because it says with for both.

If you can replace with by by means of, drop the preposition. If you can replace it by together with, keep s / sa. Saying idem sa autobusom sounds as if the bus is your friend.