После работы я зайду в аптеку и заодно куплю хлеб.

Because после requires the genitive case.

• работа = work in the dictionary form
• работы = genitive singular

So после работы literally means after work.

This is a very common pattern:

• после урока = after the lesson
• после обеда = after lunch
• после фильма = after the film

Here работы is genitive singular, not plural. The phrase means after work as a general activity or workday, not after the works or after jobs.

Russian often uses the singular in expressions like this:

• после школы = after school
• после университета = after university
• после работы = after work

So this is just the normal idiomatic way to say it.

Зайду is the 1st person singular future of зайти, a perfective verb.

In this sentence, зайти в аптеку means something like:

• to stop by the pharmacy
• to go into the pharmacy
• to drop in at the pharmacy

It often suggests a quick visit on the way somewhere or during another trip, not just the basic idea of going.

So я зайду в аптеку is more natural here than simply saying я пойду в аптеку, because the speaker is mentioning a short, purposeful stop after work.

In Russian, many future meanings are built directly into the verb form.

Зайду already means I will stop by / I will go in.
You do not need a separate word for will.

This happens because зайти is a perfective verb, and perfective verbs form a simple future:

• я зайду = I will stop by
• я куплю = I will buy

By contrast, imperfective verbs use быть for the future:

• я буду заходить = I will be stopping by / I will stop by repeatedly
• я буду покупать = I will be buying

Because the sentence describes motion toward/into the pharmacy.

With в:

• в + accusative = motion into / to
• в + prepositional = location in / at

So:

• зайду в аптеку = I will go into the pharmacy
• я в аптеке = I am in the pharmacy

Here the speaker is going there, so аптеку is accusative.

They are close, but not identical.

• пойду в аптеку = I’ll go to the pharmacy
• зайду в аптеку = I’ll stop by the pharmacy / I’ll drop into the pharmacy

Зайду often sounds more like a brief stop as part of a route or plan. That fits well with после работы and заодно.

So the sentence gives the feeling: After work, I’ll stop by the pharmacy and while I’m at it I’ll buy bread too.

Заодно means something like:

• while I’m at it
• at the same time
• along the way
• since I’m there anyway

It connects two actions and shows that the second one is convenient because of the first one.

So:

• зайду в аптеку = I’ll stop by the pharmacy
• и заодно куплю хлеб = and while I’m at it, I’ll buy bread too

It is a very natural everyday word.

Куплю is the perfective future of купить, meaning I will buy as a single completed action.

That works well here because the speaker means one simple result: I’ll buy bread.

Compare:

• куплю хлеб = I’ll buy bread
• буду покупать хлеб = I’ll be buying bread / I’ll buy bread regularly / repeatedly, depending on context
• покупаю хлеб = I buy bread / I am buying bread

So куплю is the natural choice for a one-time future action.

Russian has no articles like a or the.

So:

• в аптеку can mean to a pharmacy or to the pharmacy
• хлеб can mean bread, some bread, or the bread, depending on context

Russian usually leaves this to context. In this sentence, English would most naturally say:

• stop by the pharmacy
• buy some bread

But Russian does not need separate article words for that.

Not necessarily. Хлеб is often used in Russian the same way bread is used in English: as a general mass noun.

So куплю хлеб simply means I’ll buy bread or I’ll buy some bread.

Depending on context, it may imply a loaf, but Russian often does not spell that out unless necessary. If you wanted to be more specific, you could say:

• буханку хлеба = a loaf of bread

But in everyday speech, купить хлеб is completely normal.

Yes, Russian often can omit subject pronouns, because the verb ending already shows the person.

• зайду already means I will stop by
• куплю already means I will buy

So После работы зайду в аптеку и заодно куплю хлеб is also perfectly natural.

Including я can make the subject slightly clearer or more explicit, or it may simply reflect the speaker’s style.

The sentence is natural as written, but Russian word order is more flexible than English word order.

The neutral version is: После работы я зайду в аптеку и заодно куплю хлеб.

You could also hear variations such as:

• Я после работы зайду в аптеку и заодно куплю хлеб.
• В аптеку я зайду после работы и заодно куплю хлеб.

These versions may shift emphasis slightly, but the basic meaning stays the same.

Russian often uses word order to highlight what is new, important, or contrasted, rather than to mark grammar as strictly as English does.

Usually yes, though it can also be translated as chemist’s or sometimes drugstore depending on the variety of English and the context.

In Russian, аптека is the normal place where you buy medicine, medical items, and related products. So pharmacy is the safest general translation.

Normally, no. The structure suggests two separate actions in one outing:

• first: зайду в аптеку
• second: заодно куплю хлеб

Because of заодно, the idea is while I’m out / while I’m at it, not necessarily in the same place. The speaker is just saying they will combine errands after work.

So the natural interpretation is: they’ll stop by the pharmacy, and also pick up bread somewhere on the way.