Numeriši kutije da bismo ih brzo istovarili.

Numeriši is the singular informal imperative of the verb numerisati/numerirati in the sense of to number / label with numbers.

So it means Number... or Label ... with numbers... as a command to one person.

Related forms:

• Numeriši! — to one person
• Numerišite! — to more than one person, or one person politely/formally

In this sentence, the speaker is telling one person to do something.

Because kutije is the form used here for plural.

The noun is:

• kutija = box (singular)
• kutije = boxes (plural)

In this sentence, kutije is the direct object of Numeriši, so it is in the accusative plural. For this noun, the accusative plural looks the same as the nominative plural:

• kutije = boxes

So Numeriši kutije means Number the boxes.

Da bismo introduces a purpose clause: so that we would / in order for us to.

In natural English, this sentence is often translated with:

• so that we can
• so we can
• in order for us to

So:

• da bismo ih brzo istovarili = so that we can unload them quickly

Grammatically, bismo is the 1st person plural conditional auxiliary:

• ja bih = I would
• ti bi = you would
• on/ona/ono bi = he/she/it would
• mi bismo = we would
• vi biste = you would
• oni/one/ona bi = they would

After da, this conditional form is very common for expressing purpose.

Because Serbian usually does not use the infinitive the way English does after expressions like in order to or so that.

Instead, Serbian very often uses da + verb form.

So where English says:

• Number the boxes to unload them quickly
• Number the boxes so that we can unload them quickly

Serbian prefers:

• Numeriši kutije da bismo ih brzo istovarili.

This is a very normal Serbian structure. For English speakers, one of the big adjustments is learning that Serbian often uses da-clauses where English would use an infinitive.

Ih means them.

Here it refers back to kutije (the boxes):

• Numeriši kutije — Number the boxes
• da bismo ih brzo istovarili — so that we can unload them quickly

So ih is the accusative plural pronoun.

A useful point: ih is used for plural them regardless of grammatical gender, so it can refer to masculine, feminine, or neuter plural nouns.

Because ih is a clitic pronoun, and Serbian clitics usually go early in the clause, in a fairly fixed position.

In da bismo ih brzo istovarili:

• bismo is also a clitic
• ih is a clitic too

So they come before the full lexical verb istovarili.

That is why Serbian says:

• da bismo ih brzo istovarili

and not normally:

• da bismo brzo istovarili ih

For English speakers, this word order can feel unusual at first, but it is very normal in Serbian.

Istovarili is the past active participle (often called the l-form) of the verb istovariti.

The verb istovariti means to unload.

In this sentence, it combines with bismo:

• bismo istovarili = we would unload

After da bismo, this gives the meaning of purpose:

• da bismo istovarili = so that we would/could unload

So the structure is:

• da + bismo + istovarili

No. Istovarili agrees with the subject, not with kutije.

The implied subject here is mi (we), because of bismo:

• da bismo ... istovarili = so that we would ...

So istovarili matches we, not the boxes.

Important detail:

• istovarili is masculine plural or mixed-group plural
• if the speakers were an all-female group, you could hear istovarile

So:

• da bismo ih brzo istovarili — if the group is masculine/mixed
• da bismo ih brzo istovarile — if the group is all female

Because the sentence has two different participants:

1. Numeriši — a command to one person
2. da bismo ... istovarili — the purpose involves we

So the meaning is something like:

• You number the boxes, so that we can unload them quickly

This is completely natural. The person being addressed does not have to be the same as the subject in the purpose clause.

If the speaker were commanding a group instead of one person, the first verb would change:

• Numerišite kutije da bismo ih brzo istovarili.

Brzo means quickly, and it modifies istovarili (unload).

So:

• brzo istovarili = unload quickly

Its position can sometimes change, but the version in the sentence is very natural:

• da bismo ih brzo istovarili

That order sounds smooth and standard:

• clitics first (bismo ih)
• then the adverb (brzo)
• then the main verb (istovarili)

Not exactly, but it is close in this context.

Numeriši specifically means:

• number
• mark with numbers
• assign numbers to

So if the intended action is writing 1, 2, 3... on the boxes, Numeriši kutije is a very good match.

If you wanted a broader idea of labeling, Serbian might also use another verb depending on context, but in this sentence Numeriši clearly focuses on putting numbers on the boxes.