После работы я зайду в книжный и куплю словарь.

Because после requires the genitive case, and работа in the genitive singular becomes работы.

• dictionary form: работа
• genitive singular: работы

So:

• после работы = after work

This is a very common pattern in Russian:

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

In this sentence, после работы most naturally means after work in the everyday sense: after the speaker finishes work for the day.

It usually does not mean the abstract idea of work in general. It refers to the time period after someone gets off work.

Зайду is the 1st person singular future form of зайти, which often means to drop in, to stop by, or to pop into somewhere.

So here, я зайду в книжный means something like:

• I’ll stop by the bookstore
• I’ll pop into the bookstore

It is not just neutral movement like I will go. It has the idea of entering briefly or on the way somewhere.

Because зайти is a perfective verb. In Russian, perfective verbs do not have a true present tense. Their present-looking forms actually refer to the future.

So:

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

This is a very important Russian pattern:

• сделаю = I will do
• прочитаю = I will read
• напишу = I will write

Because after a verb of motion like зайти, в usually takes the accusative when it means movement into a place.

Here the speaker is going into the bookstore, so Russian uses the accusative:

• в книжный = into the bookstore

Compare:

• в книжном = in the bookstore

So:

• Я зайду в книжный. = I’ll go into / stop by the bookstore.
• Я работаю в книжном. = I work in the bookstore.

Yes. In Russian, an adjective can sometimes stand on its own when the noun is obvious from context. This is very common in everyday speech.

So:

• книжный (магазин) = bookstore
• продуктовый (магазин) = grocery store
• ювелирный (магазин) = jewelry store

Here, в книжный is a shortened, natural way to say в книжный магазин.

Yes, absolutely.

Both are correct:

• Я зайду в книжный.
• Я зайду в книжный магазин.

The shorter version sounds very natural in conversation. The longer version is a bit more explicit.

Словарь is the direct object of куплю, so it is in the accusative case. But for many masculine inanimate nouns, the accusative singular is the same as the nominative singular.

So:

• nominative: словарь
• accusative: словарь

That is why the word does not visibly change.

Compare with a feminine noun, where you often do see a change:

• книга → книгу

Because the subject is the same for both verbs, so Russian often omits the repeated pronoun.

• я зайду и куплю = I’ll stop by and buy

You could say я зайду в книжный и я куплю словарь, but it sounds unnecessary unless you want special emphasis.

This is similar to English, where we also usually say:

• I’ll stop by the bookstore and buy a dictionary

not

• I’ll stop by the bookstore and I’ll buy a dictionary

Yes. Both actions are presented as single completed future events:

• зайду = I’ll stop by
• куплю = I’ll buy

The speaker is talking about a concrete plan: one visit, one purchase.

If you used imperfective verbs, the meaning would change and sound less natural here unless you meant process, repetition, or a more general future situation.

Not with exactly the same meaning.

• Я пойду в книжный = I’ll go to the bookstore
• Я зайду в книжный = I’ll stop by / pop into the bookstore

Пойду focuses on going there. Зайду suggests a brief visit or dropping in, often as one step in a larger plan.

So зайду is a little more specific and natural here.

И simply means and, connecting the two future actions:

• зайду = I’ll stop by
• куплю = I’ll buy

So the sentence describes a sequence of actions:

1. after work
2. I’ll stop by the bookstore
3. and I’ll buy a dictionary

Yes. Russian word order is flexible, and changing it changes emphasis more than basic meaning.

The original:

• После работы я зайду в книжный и куплю словарь.

This is neutral and natural.

Other possible orders:

• Я после работы зайду в книжный и куплю словарь.
  Slightly more focus on I or on the overall statement.

• В книжный я зайду после работы и куплю словарь.
  More focus on the bookstore.

• Словарь я куплю после работы, зайду в книжный.
  More marked; stronger focus on dictionary.

For learners, the original version is the best neutral model.

It comes from книга = book.

The adjective книжный means book-related or bookstore-type depending on context. In this sentence it stands for книжный магазин, literally book store.

So the connection is:

• книга = book
• книжный магазин = bookstore
• в книжный = into the bookstore

The main stresses are:

• послЕ
• рабОты
• зайдУ
• в кнИжный
• и куплЮ
• словАрь

Stress is very important in Russian, because it is not always predictable and can change from form to form.