Imamo štedni plan: svaki mjesec uplatimo malo novca da ne bismo opet bili u minusu.

Croatian often leaves subject pronouns out because the verb ending already shows who the subject is.

• imamo = we have
• uplatimo = we pay in / we make a payment
• bismo bili = we would be

So mi is unnecessary unless you want emphasis or contrast, for example: Mi imamo štedni plan, a oni nemaju. = We have a savings plan, but they don’t.

Štedni plan means a savings plan.

The adjective štedni comes from the idea of saving money:

• štedjeti = to save
• štednja = saving(s)
• štedni = savings-, thrift-related

So štedni plan is a plan for saving money. You could also hear expressions like:

• plan štednje = savings plan
• štedni račun = savings account

Svaki mjesec is a common way to say every month.

Here svaki agrees with mjesec, and the whole expression functions as a time expression. Croatian often uses the accusative for repeated time expressions:

• svaki dan = every day
• svaki tjedan = every week
• svaki mjesec = every month

You may also hear svakog mjeseca, which is also correct and very common. The difference is small here; both mean every month.

Uplatimo comes from uplatiti, which means to pay in, to deposit, or to make a payment.

In this sentence, it means that each month we put in some money. The prefix u- gives the idea of paying money into an account, fund, or plan.

So:

• platiti = to pay
• uplatiti = to pay in / deposit

This is a very common verb in financial contexts.

This is mainly about aspect.

• uplatiti → perfective
• uplaćivati → imperfective

So:

• uplatimo presents each monthly payment as a complete act
• uplaćujemo would emphasize the ongoing or habitual process

In English, both may translate similarly, but Croatian aspect adds nuance. In a sentence like this, uplatimo works well because the idea is each month we make a payment as one completed step in the plan.

Because malo here means a little or a small amount of, not small.

So:

• malo novca = a little money / a small amount of money
• mali novac would mean small money, which is not what you want here

Also, after quantity words like malo, Croatian usually puts the noun in the genitive:

• malo vode = a little water
• malo vremena = a little time
• malo novca = a little money

Here novca is the genitive singular of novac.

Here da ne bismo introduces a purpose clause: it explains why they pay in money every month.

So the meaning is roughly:

• so that we wouldn’t...
• in order not to...

In the full sentence:

• da ne bismo opet bili u minusu = so that we wouldn’t be in the red again

This is a very common Croatian structure for expressing purpose, especially when the purpose is to avoid something bad.

Because that is how the Croatian conditional is formed.

The conditional uses:

• the auxiliary bih, bi, bismo, biste...
• plus the l-participle of the main verb

For biti (to be), that gives:

• bismo bili = we would be

So even though it may look repetitive to an English speaker, it is completely normal Croatian grammar.

Because bili is the masculine plural form, and Croatian uses masculine plural as the default for:

• mixed-gender groups
• unspecified groups

If the group were entirely female, you would say:

• da ne bismo opet bile u minusu

So:

• bili = we would be, masculine/mixed plural
• bile = we would be, feminine plural

U minusu is an idiomatic financial expression meaning:

• in the red
• overdrawn
• in deficit
• with a negative balance

Literally, it is something like in minus, but in normal English you would usually not translate it word for word.

Its opposite is:

• u plusu = in profit / in the black / with a positive balance

Because bismo is a clitic, and Croatian clitics usually go near the beginning of the clause.

So the normal order is:

• da ne bismo opet bili u minusu

not:

• da ne opet bismo bili...

This kind of word order is very typical in Croatian. Clitics such as sam, si, je, smo, ste, su, bih, bi, bismo usually do not stand freely wherever you want.

Opet means again.

So:

• da ne bismo opet bili u minusu = so that we wouldn’t be in the red again

It shows that being u minusu has happened before, and they want to avoid a repeat. You could often replace it with ponovno, but opet is very common and natural in everyday Croatian.