Jeśli nie masz dużych oszczędności, lepiej nie brać pożyczki na nowy samochód.

Jeśli means if. It introduces a condition:

• Jeśli nie masz dużych oszczędności... = If you do not have large savings...

It is one of the most common ways to form an if-clause in Polish.

Masz is the 2nd person singular form of mieć = to have.

So:

• mam = I have
• masz = you have
• ma = he/she/it has

The sentence is addressing one person directly, so masz is the correct form.

In Polish, oszczędności is very commonly used as a plural noun meaning savings.

That works much like English savings, which is also plural in form:

• mam oszczędności = I have savings

You can think of it as referring to saved money as a collection, not a single item.

Because after a negated verb, Polish often uses the genitive instead of the accusative for the direct object.

Compare:

• Masz duże oszczędności. = You have large savings.
• Nie masz dużych oszczędności. = You do not have large savings.

So both words change:

• duże → dużych
• oszczędności stays the same in form here, but it is functioning as genitive plural

This is a very important Polish pattern.

Literally, it is something like better not to take.

Here lepiej means better, and nie brać is not to take.

Polish often uses this kind of impersonal advice structure:

• Lepiej poczekać. = It is better to wait.
• Lepiej nie jechać. = It is better not to go.
• Lepiej nie brać pożyczki. = It is better not to take out a loan.

In natural English, you would usually translate it as:

• you’d better not take out a loan
• it’s better not to take out a loan

Because the verb is negated: nie brać.

With negation, Polish often changes the object into the genitive:

• brać pożyczkę = to take out a loan
• nie brać pożyczki = not to take out a loan

So:

• pożyczkę = accusative singular
• pożyczki = genitive singular

This is the same negation pattern you see in nie masz dużych oszczędności.

This is an aspect question.

• brać = imperfective
• wziąć = perfective

In advice about general behavior, Polish often prefers the imperfective:

• lepiej nie brać pożyczki = better not to be taking / better not to take out a loan in general

Using brać makes the advice sound more general and less focused on one single completed act.
A perfective version can be possible in some contexts, but lepiej nie brać pożyczki sounds very natural as general advice.

Yes, in this context brać pożyczkę means to take out a loan or to borrow money.

Literally, brać means to take, but Polish often uses it in expressions like:

• brać kredyt = to take out a loan / get a loan
• brać pożyczkę = to take out a loan

So do not translate brać too mechanically here. The full phrase is what matters.

It is accusative after the preposition na.

Here na means for, in the sense of for the purpose of buying something:

• pożyczka na nowy samochód = a loan for a new car

Samochód is a masculine inanimate noun, and in the accusative singular it looks the same as the nominative:

• nominative: nowy samochód
• accusative: nowy samochód

So the form does not change, but the case is still accusative.

Because the sentence begins with a subordinate if-clause:

• Jeśli nie masz dużych oszczędności, ...

In Polish, when a subordinate clause comes before the main clause, it is normally separated by a comma.

So the structure is:

• Jeśli... , lepiej...

This is standard punctuation.

Sometimes yes, but jeśli is the most straightforward choice for if.

For example, gdy or kiedy can sometimes mean if/when depending on context, but they are not always interchangeable. In this sentence, jeśli is the clearest and most neutral way to express a condition.

So for a learner, Jeśli nie masz..., lepiej... is a very good model to remember.

It is neutral, standard Polish. It sounds natural in both speech and writing.

It is not slang, and it is not especially formal either. It is the kind of sentence you might hear in financial advice, everyday conversation, or an article about money.