W twoim nazwisku jest mała literówka.

Because w meaning in takes the locative case when it describes location.

• dictionary form: nazwisko = surname / last name
• locative singular: nazwisku

The possessive adjective twój also has to match that case:

• twój → twoim in the locative singular neuter

So:

• w nazwisku = in the surname
• w twoim nazwisku = in your surname

If you said w twoje nazwisko, that would be incorrect here.

Nazwisku is the locative singular form of nazwisko.

Polish nouns change form depending on their role in the sentence. After w meaning in, when talking about being inside something or located somewhere, you usually use the locative:

• nazwisko → w nazwisku
• dom → w domu
• szkole from szkoła → w szkole

So nazwisku is simply the correct case form after w.

Twoim is the form of twój that agrees with nazwisku.

Since nazwisku is:

• singular
• neuter
• locative

the possessive adjective must match all of that:

• twój → twoim

Compare:

• twój dom = your house
• w twoim domu = in your house
• twoje nazwisko = your surname
• w twoim nazwisku = in your surname

So the ending changes because Polish adjectives and possessives must agree with the noun.

Because literówka is a feminine noun.

The adjective mały has to agree with the noun in:

• gender
• number
• case

So:

• masculine: mały
• feminine: mała
• neuter: małe

Since literówka is feminine, you get:

• mała literówka

Literówka means typo: a small accidental mistake in writing, especially a wrong letter, missing letter, or extra letter.

Examples:

• To tylko literówka. = It’s just a typo.
• Masz literówkę w imieniu. = You have a typo in your first name.

It is more specific than a general mistake.

• błąd = error / mistake in general
• literówka = typo

So in this sentence, the speaker is saying there is a small spelling/typing mistake in the surname.

Jest means is, and here the structure is basically:

• W twoim nazwisku jest mała literówka.
• literally: In your surname is a small typo.
• natural English: There is a small typo in your surname.

Polish often uses jest in this kind of there is / there are sentence.

So jest is not just a plain is joining two nouns; it is introducing the existence of something.

Yes, that is very normal.

The sentence starts with the place:

• W twoim nazwisku = in your surname

Then it says what exists there:

• jest mała literówka = there is a small typo

This word order is natural because it presents the location first and then the thing found there.

You could also say:

• Mała literówka jest w twoim nazwisku.

But that sounds less natural in ordinary conversation unless you want to emphasize mała literówka.

The usual, neutral version is:

• W twoim nazwisku jest mała literówka.

Literally yes, but in this sentence it means something more like:

• minor
• slight
• just a tiny

So mała literówka is not about physical size. It means the typo is small or not serious.

In English we often say things like:

• a small typo
• a little mistake

Polish works similarly here.

Yes, absolutely.

That means:

• There is a typo in your surname.

Adding mała makes it softer or more reassuring:

• jest literówka = there is a typo
• jest mała literówka = there is a small typo / just a tiny typo

Both are correct. The version with mała can sound a bit gentler.

Yes. Nazwisko specifically means surname / last name / family name.

Compare:

• imię = first name / given name
• nazwisko = surname / last name
• imię i nazwisko = full name

So this sentence is specifically about the person’s surname, not their name in general.

A rough pronunciation guide is:

v TFO-yeem naz-VEES-koo yest MA-wa lee-te-ROOF-ka

A few useful notes:

• w is pronounced like English v
• twoim sounds roughly like tfoy-im, because tw is pronounced with a devoiced t/f-like effect before a voiceless consonant
• rz in nazwisku sounds like zh or often like sh here because of devoicing
• ł in mała sounds like English w
• stress is usually on the second-to-last syllable:
  • twoim
  • nazwisku
  • literówka

It is fairly neutral and normal. It simply points out a typo.

Still, depending on context, Polish speakers might soften it a little, for example:

• W twoim nazwisku jest chyba literówka. = I think there’s a typo in your surname.
• Chyba jest mała literówka w twoim nazwisku. = There seems to be a small typo in your surname.
• Wydaje mi się, że w twoim nazwisku jest literówka. = It seems to me that there’s a typo in your surname.

So the original sentence is correct and natural, but if you want to sound more careful or polite, adding chyba or wydaje mi się helps.

Yes, and that is also natural.

• Masz literówkę w nazwisku. = You have a typo in your surname.

This version focuses more directly on you have something wrong there.

The original:

• W twoim nazwisku jest literówka.

focuses more on the typo existing in the surname.

Both are common, but the original sounds a little more impersonal and sometimes slightly gentler.