A cidade em que minha avó mora fica longe daqui.

Here em que means in which.

So:

• a cidade = the city
• em que = in which
• minha avó mora = my grandmother lives

A very literal structure is:

The city in which my grandmother lives...

In Portuguese, em is the preposition in, and que is a relative word connecting cidade to the rest of the clause.

Yes. Onde is very common here.

So you can say:

• A cidade em que minha avó mora fica longe daqui.
• A cidade onde minha avó mora fica longe daqui.

Both are correct. In everyday Brazilian Portuguese, onde often sounds more natural and conversational.

Very generally:

• em que = a bit more formal or neutral
• onde = very common for places

Because cidade is a place, onde works very well.

Because the subject is minha avó, which is singular.

• eu moro = I live
• você/ele/ela mora = you/he/she lives
• eles/elas moram = they live

In the sentence, the verb agrees with minha avó, not with cidade.

So:

• minha avó mora = my grandmother lives

Even though cidade appears earlier, it is not the one doing the action of living.

Here fica means something like is located or is situated.

So fica longe daqui means:

• is far from here
• more literally, is located far from here

Portuguese often uses ficar when talking about where a place is:

• Onde fica o banco? = Where is the bank?
• Minha escola fica perto de casa. = My school is near home.

So in this sentence, fica is not really becomes; it is the location meaning of ficar.

Portuguese often prefers ficar when describing the location of places.

• fica longe daqui = is located far from here

Using é longe can also exist in some contexts, but fica longe sounds more natural when you mean physical location.

Compare:

• A cidade fica longe daqui. = The city is far from here. / The city is located far from here.
• É longe. = It’s far.

So ficar is especially common when talking about where something is.

Because daqui is the normal contracted form meaning from here.

• de + aqui = daqui

This kind of contraction is very common in Portuguese:

• de + o = do
• de + a = da
• em + a = na
• em + o = no

So:

• longe daqui = far from here

You should learn daqui as a single very common word.

Good question. In Brazilian Portuguese, both patterns can be found:

• minha avó
• a minha avó

Both can be correct.

In Brazil, leaving out the article before a possessive is very common, especially in simpler, more neutral sentences. So minha avó sounds completely natural.

Depending on region, style, or emphasis, you may also hear:

• A cidade em que a minha avó mora...

That is also fine.

Because Portuguese usually uses the definite article here.

• a cidade = the city

In English, you also normally need the city in a sentence like this. Portuguese works similarly here.

Saying just cidade would usually sound incomplete in this context.

A little, but it is actually quite close.

Portuguese: A cidade em que minha avó mora fica longe daqui.

Very literal English: The city in which my grandmother lives is far from here.

The main difference is that Portuguese uses em que where English might use:

• in which (formal)
• that ... in or which ... in in some structures
• often just where in natural speech

So the structure may feel slightly formal if you translate it word for word, but in Portuguese it is perfectly normal.

Yes, but morar is the most natural verb when talking about the place where someone lives.

• morar = to live somewhere, to reside
• viver = to live, but often broader, like life in general

So:

• A cidade onde minha avó mora... = the city where my grandmother lives

You could sometimes hear vive, but mora is the usual choice for residence.

Yes, but many speakers would probably choose the slightly more conversational version:

• A cidade onde minha avó mora fica longe daqui.

The version with em que is absolutely correct and natural, but it can sound a bit more careful or formal than onde.

So for everyday speech:

• onde is very common
• em que is also correct and useful to know

A very natural everyday version would be:

• A cidade onde minha avó mora fica longe daqui.

Another possible spoken version, depending on context, might be:

• A cidade que minha avó mora fica longe daqui.

However, that last version is common in speech but may be considered less standard by some grammar guides, because the standard form expects the preposition: onde or em que.

So if you want a safe, natural option, use:

• A cidade onde minha avó mora fica longe daqui.