Learn Hardcore Czech: Moje sestra píše o našem městě a o jménu ulice. - My sister writes about our city and about the name of the street.

můj = my (for masculine nouns, e.g. můj bratr – my brother)
moje = my (for feminine and neuter nouns, e.g. moje sestra, moje město)

So you must say Moje sestra, not Můj sestra.

Can I also say Má sestra instead of Moje sestra? Is there any difference?

Yes, you can say Má sestra. It is grammatically correct and means the same thing as Moje sestra: my sister.

Difference in style:

Moje sestra – neutral, everyday, most common in modern spoken Czech.
Má sestra – a bit more formal, concise, slightly bookish or literary in feel, but still used in normal language.

So both are correct; Moje sestra is simply the more neutral choice for everyday speech.

What exactly does píše mean? Is it “writes” or “is writing”?

Píše is the 3rd person singular present tense of psát (to write).

In English, it can correspond to both:

She writes (habit, regular action)
She is writing (action happening now)

Czech doesn’t have a separate continuous form, so píše covers both meanings; the context tells you whether it is a general habit or something happening right now.

Why is it o našem městě and not o naše město?

Because the preposition o (“about”) requires the locative case in this meaning.

Nominative (dictionary form): město – a town / city
Locative singular: městě

So with o in the sense of about, you must use the locative: o městě = about the town.

The possessive pronoun náš (“our”) also changes to the locative form to agree with městě:

Nominative neuter: naše město – our town
Locative neuter: o našem městě – about our town

So o naše město is incorrect here; it must be o našem městě.

How do našem and městě agree with each other?

They agree in:

Gender: město is neuter; našem is the neuter form of náš in the locative.
Number: both are singular.
Case: both are in the locative singular.

Pattern:

Nominative: naše město (our town)
Locative: o našem městě (about our town)

This kind of agreement (gender + number + case) between adjectives/possessives and nouns is a core rule in Czech.

Why is it městě with ě, and how is it pronounced?

In the locative singular, město changes to městě.

Spelling: mě is used after m to show a palatalized sound; historically it comes from mje.
Pronunciation: mě is pronounced roughly like m-nye; městě sounds like [mɲestě].

So město ≈ MYE-stoh, městě ≈ MYE-stye (approximation for an English ear).

Why is o repeated: o našem městě a o jménu ulice? Could I drop the second o?

Both versions are possible:

Moje sestra píše o našem městě a o jménu ulice.
Moje sestra píše o našem městě a jménu ulice.

Meaning is the same: My sister writes about our town and about the name of the street.

Repeating o (version 1) is clearer and a bit more careful/explicit.
Omitting the second o (version 2) is also correct and fairly natural in speech when the structure is obvious.

Beginners usually find it clearer to repeat o in both parts.

What case is jménu and why is it used here?

Jménu is in the locative singular of jméno (name).

Declension (important cases):

Nominative: jméno – name
Genitive: jména – of the name
Dative/Locative: jménu – to the name / about the name

Because the preposition o in this sentence means “about”, it demands the locative case, so:

o jménu = about the name

That’s why jménu is used here.

Are o jménu and o jméně both correct?

Yes, both o jménu and o jméně are possible locative forms of jméno.

In modern standard Czech, o jménu is more common and neutral.
o jméně is also correct but can sound a bit more formal or stylistic; you see it especially in some fixed phrases or more literary language.

So in your sentence o jménu ulice is fully standard and natural.

What case is ulice in jménu ulice, and what does that structure mean?

Ulice here is in the genitive singular of ulice (street).

Nominative singular: ulice – a street
Genitive singular: ulice – of a street

The form happens to look the same in nominative and genitive.

The structure jméno ulice literally means “the name of the street”, just like a typical noun + noun in genitive construction in other languages (e.g. “roof of the house”, “color of the car”).

So o jménu ulice means about the name of the street.

Could I change the word order, for example: Moje sestra o našem městě píše a o jménu ulice?

You can change the word order quite flexibly in Czech. Some natural options:

Moje sestra píše o našem městě a o jménu ulice. (original, very natural)
Moje sestra o našem městě a o jménu ulice píše. (puts more focus on what she writes about)
O našem městě a o jménu ulice píše moje sestra. (focuses on the topics first, then “my sister”)

Your example Moje sestra o našem městě píše a o jménu ulice is incomplete – after a o jménu ulice we still “feel” the verb píše, but it’s missing at the end. More natural would be:

Moje sestra o našem městě píše a také o jménu ulice.

In general, Czech allows word order changes for emphasis, but each version must still sound complete and natural in context.

How would I say “My sister wrote about our town and about the name of the street” (a finished action in the past)?

You would typically use the perfective verb napsat (to write, complete an act of writing) in the past tense:

Moje sestra napsala o našem městě a o jménu ulice.

Here:

napsala = she wrote (and finished writing)
The rest of the sentence stays the same, including the cases after o.

If you used the imperfective psát in the past (psala), it would focus more on the process or a repeated action:

Moje sestra psala o našem městě a o jménu ulice.
= She was writing / used to write about our town and about the name of the street.