Mio marito passa in tabaccheria ogni sabato, mentre io vado in edicola.

In Italian, singular family members usually take a possessive without the article:

• mio marito
• mia moglie
• mio fratello
• mia sorella

So mio marito is the normal form.

You often do use the article with:

• plural family members: i miei genitori
• modified family members: il mio fratello maggiore
• sometimes for emphasis or in regional usage, but that is not the standard beginner rule

So in this sentence, mio marito is exactly what you would expect.

Here passare in tabaccheria means something like:

• to stop by the tobacconist's
• to drop into the tobacco shop
• to pop into the tobacconist's

It does not mean simply to pass in the English sense of moving past something.

Italian passare is often used for a brief stop or visit:

• Passo in banca = I stop by the bank
• Passo al supermercato = I stop by the supermarket

So Mio marito passa in tabaccheria ogni sabato suggests a regular quick visit there every Saturday.

With many shops and businesses, Italian often uses in + place name without an article when talking about going there in a general way:

• in banca
• in farmacia
• in tabaccheria
• in edicola

This is very natural Italian.

If you want to specify a particular one, you may use an article or another structure:

• nella tabaccheria sotto casa = in the tobacconist's near our house
• nell’edicola della stazione = in the newsstand at the station

So in your sentence, the article is omitted because the speaker is talking about the place type in a general, routine sense.

Italian choice of preposition depends a lot on the noun and the kind of place.

With many businesses or enclosed places, in is common:

• in tabaccheria
• in edicola
• in farmacia
• in banca

With some other places, a is more common:

• a casa
• a scuola
• al supermercato

Unfortunately, this is something you often learn by exposure rather than by a single universal rule. In this sentence, in tabaccheria and in edicola are the standard idiomatic forms.

A tabaccheria is a tobacco shop, but in Italy it often sells much more than tobacco products. Depending on the place, it may also sell things like:

• stamps
• lottery tickets
• bus tickets
• phone top-ups
• stationery items
• official payment services

So it is a very common everyday shop in Italy, and learners often notice that it does more than the English word tobacconist's might suggest.

An edicola is a newsstand or kiosk where people buy things like:

• newspapers
• magazines
• comics
• sometimes small stationery items or collectibles

So vado in edicola means I go to the newsstand.

Because Italian commonly uses the simple present for habitual actions, just like English often does:

• Ogni sabato passa in tabaccheria = Every Saturday he stops by the tobacconist's
• La mattina bevo caffè = In the morning I drink coffee

So the present tense here means a repeated routine, not necessarily something happening right now.

Here mentre means while, but it can also carry a contrast similar to whereas or while on the other hand.

In this sentence, it links two actions and lightly contrasts them:

• Mio marito passa in tabaccheria ogni sabato
• mentre io vado in edicola

So the sense is something like:

• My husband stops by the tobacconist's every Saturday, while I go to the newsstand.

It is not a strong opposition, just a comparison between what the two people do.

Yes, Italian often omits subject pronouns because the verb ending already tells you who the subject is.

So vado in edicola would already mean I go to the newsstand.

But io is included here for contrast:

• Mio marito does one thing,
• io do another.

So mentre io vado in edicola feels like:

• while I, on the other hand, go to the newsstand

This is a very common reason to include a subject pronoun in Italian.

Yes, but the nuance changes.

• va in tabaccheria = he goes to the tobacconist's
• passa in tabaccheria = he stops by / drops into the tobacconist's

Passa suggests a brief or routine stop, often on the way somewhere or as part of a regular habit. Va is more neutral and simply says he goes there.

So the original sentence sounds a bit more natural if the idea is a quick regular stop.

Ogni sabato means every Saturday, and its position here is very natural:

• Mio marito passa in tabaccheria ogni sabato

Italian is fairly flexible with adverbial expressions like this. You could also hear:

• Ogni sabato mio marito passa in tabaccheria

Both are correct. The original version sounds neutral and smooth.

Yes. They often appear without an article in general expressions, but they can take one when you mean a specific place.

Compare:

• Vado in edicola = I’m going to the newsstand
• Vado nell’edicola vicino alla stazione = I’m going to the newsstand near the station

And:

• Passa in tabaccheria = He stops by the tobacconist's
• Passa nella tabaccheria all’angolo = He stops by the tobacconist's on the corner

So the article appears when the place is more specifically identified.

Yes: it is a very typical Italian pattern for describing habits and contrast.

Structure:

• Mio marito = subject
• passa in tabaccheria = verb + destination/place
• ogni sabato = time expression
• mentre io vado in edicola = contrasting clause

So the sentence is built in a very natural everyday way:

1. state what one person regularly does
2. add a contrasting or parallel action with mentre

It is a useful model you can reuse, for example:

• Mia sorella va in palestra, mentre io resto a casa.
• Lui compra il giornale, mentre io prendo un caffè.