Бывший сотрудник теперь работает здесь.

Бывший means former or ex- when talking about a person’s previous role, position, or relationship.

So:

• бывший сотрудник = former employee
• бывший муж = ex-husband

You usually use бывший for something that someone used to be, but is not anymore.

By contrast, прошлый usually means last or previous in a more general sense:

• прошлый год = last year
• прошлая неделя = last week

So прошлый сотрудник would sound wrong for former employee in this context.

It is in the nominative singular, because it is the subject of the sentence.

The sentence answers the question Who works here now?

• бывший сотрудник = the subject
• теперь работает = now works
• здесь = here

Since Russian marks grammatical roles with case, the subject normally appears in the nominative case.

In the present tense, Russian usually does not use a verb meaning to be in sentences like this.

English:

• The former employee is here.
• He is a teacher.

Russian:

• Бывший сотрудник здесь.
• Он учитель.

In your sentence, the main verb is работает (works), so there is no need for any extra is.

Теперь means now, but more in the sense of now / from now on / at the present stage, often contrasting with the past.

In this sentence:

• Бывший сотрудник теперь работает здесь.
• The former employee now works here.

This suggests a change from an earlier situation.

Сейчас also often means now, but more like right now / at this moment.

Compare:

• Теперь он работает здесь. = He works here now. / He now works here.
• Сейчас он работает. = He is working now / at the moment.

In many situations they overlap, but теперь is especially good when you are emphasizing a new state or change.

The dictionary form is работать = to work.

Russian verbs change depending on the subject. Here the subject is он / бывший сотрудник, which is third person singular, so:

• я работаю = I work
• ты работаешь = you work
• он/она работает = he/she works
• мы работаем = we work
• они работают = they work

So работает means works / is working depending on context.

Also, Russian infinitives end in -ть, so работать is correct, but работаеть is not.

Yes. Russian present-tense forms often cover both:

• works
• is working

So работает can mean either, depending on context.

In this sentence, because of теперь and the overall meaning, the most natural translation is:

• now works here

rather than

• is working here right now

If you wanted to emphasize the action happening at this exact moment, context or words like сейчас would help.

Yes, Russian word order is quite flexible.

The neutral word order here is:

• Бывший сотрудник теперь работает здесь.

But other orders are possible:

• Теперь бывший сотрудник работает здесь.
• Здесь теперь работает бывший сотрудник.

The basic meaning stays similar, but the focus changes.

For example:

• Бывший сотрудник теперь работает здесь.
  Neutral: the former employee now works here.

• Здесь теперь работает бывший сотрудник.
  Stronger focus on here or on the fact that it is the former employee who works here.

English relies more on word order; Russian can use word order more freely for emphasis.

Yes, often you can.

• здесь = here
• тут = here

In many everyday situations they are interchangeable:

• Он работает здесь.
• Он работает тут.

Both are natural.

Very roughly:

• здесь can sound a little more neutral or standard
• тут can sound a little more conversational

But the difference is usually small.

Both can refer to a worker or employee, but сотрудник is often the more natural word for employee / staff member / colleague in many modern contexts.

• сотрудник компании = company employee
• сотрудник полиции = police officer / police employee
• научный сотрудник = research associate / researcher

Работник can also mean worker/employee, but it can sound more formal, official, or broader in meaning, depending on context.

So for former employee, бывший сотрудник sounds very natural.

By itself, бывший сотрудник means a former employee. It does not automatically specify of where.

So this sentence means:

• The former employee now works here.

That could mean:

• someone who used to be an employee somewhere else and now works here, or
• depending on context, someone who used to work for this place and now works here again

If you want to say exactly whose former employee, Russian often adds that information:

• бывший сотрудник компании = a former employee of the company
• бывший сотрудник банка = a former bank employee

Context usually tells you the rest.

Russian has no articles like a/an/the.

So:

• сотрудник can mean an employee or the employee
• бывший сотрудник can mean a former employee or the former employee

Which one is meant depends on context.

In your sentence, English might translate it as either:

• The former employee now works here
• A former employee now works here

The Russian sentence itself does not mark that difference directly.

You would change the adjective and probably use the feminine noun if you want to make the person clearly female:

• Бывшая сотрудница теперь работает здесь.

Breakdown:

• бывшая = feminine form of former
• сотрудница = female employee
• работает stays the same in the present tense

Russian adjectives must agree with the noun in gender, number, and case.

Russian adjectives agree with the nouns they describe.

Here:

• бывший = masculine, singular, nominative
• сотрудник = masculine, singular, nominative

They match perfectly.

If the noun changed, the adjective would change too:

• бывшая сотрудница = former female employee
• бывшие сотрудники = former employees

This agreement is one of the most important patterns in Russian grammar.

The stress is:

• бы́вший
• сотру́дник
• тепе́рь
• рабо́тает
• здесь (one syllable, so no issue)

A rough pronunciation guide:

• бы́вший ≈ BYV-shee
• сотру́дник ≈ sa-TROOD-neek
• тепе́рь ≈ tye-PYER’
• рабо́тает ≈ ra-BO-ta-yet

Stress matters in Russian, so it is worth learning words together with their stress.

Yes:

• Бывший сотрудник работает здесь.

That means simply:

• The former employee works here.

Adding теперь makes the time contrast clearer:

• Бывший сотрудник теперь работает здесь.
• The former employee now works here.

So теперь is not required for grammar, but it adds important meaning.