Этот помощник работает быстро.

Этот means this and is a demonstrative pronoun. It agrees with the noun помощник in gender, number, and case.

Here, помощник is:

• masculine
• singular
• nominative case (the subject of the sentence)

So the correct form is этот.

Some related forms are:

• эта for feminine singular
• это for neuter singular
• эти for plural

For example:

• эта машина = this car
• это окно = this window
• эти люди = these people

Помощник means assistant or helper.

Yes, it is grammatically masculine. In Russian, many masculine nouns end in a consonant, and помощник ends in -к, so it follows a typical masculine pattern.

Its nominative singular form is помощник.
Other forms include:

• помощника = of the assistant / assistant (object, depending on case)
• помощнику = to the assistant

Even if the real assistant were female, the noun itself is still grammatically masculine unless you use a different noun, such as помощница for a female assistant.

In Russian, the present tense often covers both:

• works
• is working

So работает can mean either one, depending on context.

Russian does not have a separate verb form exactly like the English progressive is working. Instead, context tells you whether the meaning is habitual or happening right now.

So this sentence could mean:

• This assistant works quickly
• This assistant is working quickly

If there is no extra context, English learners often translate it as the more general works quickly.

Работает is the 3rd person singular present tense form of работать (to work).

That means it is used with:

• he
• she
• it
• singular nouns like помощник

Conjugation:

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

So in Этот помощник работает быстро, the subject is singular, so работает is the correct form.

Быстро is an adverb, and adverbs describe how an action is done.

Here it describes работает:

• работает быстро = works quickly

If you used an adjective, it would describe a noun, not the action itself.

Compare:

• быстрый помощник = a fast assistant
• помощник работает быстро = the assistant works quickly

So быстро is correct because the sentence is talking about the manner of working, not directly describing the assistant as a noun.

Yes. Russian word order is more flexible than English word order because case endings help show grammatical roles.

The neutral, straightforward order here is:

• Этот помощник работает быстро.

But other orders are possible, for example:

• Этот помощник быстро работает.
• Быстро работает этот помощник.

These versions can shift the focus or emphasis:

• Этот помощник работает быстро sounds neutral.
• Этот помощник быстро работает puts a little more focus on quickly as part of the predicate.
• Быстро работает этот помощник can sound more emphatic or contrastive, like This assistant works quickly.

Not every word order sounds equally natural in every context, but Russian allows more variation than English.

Russian usually does not use a present-tense form of to be in ordinary sentences like this.

English says:

• This assistant is fast
• This assistant is an assistant

Russian normally omits present-tense is:

• Этот помощник быстрый
• Это помощник

In your sentence, there is already a main verb, работает (works), so no separate is is needed anyway.

Historically, Russian has a verb быть (to be), but in the present tense it is usually omitted in standard sentences.

In this sentence, быстро is clearly an adverb meaning quickly.

It comes from the adjective быстрый (fast, quick). Russian often forms adverbs from adjectives, especially with endings like -о:

• быстрый → быстро
• медленный → медленно
• хороший → хорошо

So:

• быстрый помощник = a fast assistant
• работает быстро = works quickly

For learners, it is helpful to remember that -о forms are very often adverbs.

Yes. The exact English wording can vary a little.

• помощник can mean assistant or helper
• быстро can be translated as quickly or fast

So possible translations include:

• This assistant works quickly
• This assistant works fast
• This helper works quickly

The best choice depends on context and style. Works quickly is often the safest and most neutral translation for learners.

There are two main clues:

1. Nominative case
   Both этот and помощник are in the nominative form, which is the normal case for the subject.

2. Verb agreement
   Работает is a singular verb form, which matches the singular subject помощник.

So the structure is:

• Этот помощник = subject
• работает = verb
• быстро = adverb

That makes the sentence pattern very similar to:

• This assistant works quickly.

No. Russian often leaves out words like this when they are not needed.

So you could also say:

• Помощник работает быстро. = The assistant works quickly / An assistant works quickly

Adding этот makes the noun more specific:

• Этот помощник = this assistant

Russian uses demonstratives when the speaker wants to point something out, identify a specific thing, or create contrast. So этот is not required for grammar, but it adds meaning.