Этот чемодан не войдёт в багажник, поэтому мы положим его в салон.

Because чемодан is a masculine singular noun, and этот is the masculine singular form of this.

• этот = this (masculine)
• эта = this (feminine)
• это = this (neuter)
• эти = these (plural)

So:

• этот чемодан = this suitcase
• but эта сумка = this bag
• and это кресло = this armchair/seat

The adjective-like word этот has to agree with the noun in gender, number, and case.

Because чемодан is the subject of the first clause.

In Этот чемодан не войдёт в багажник, the suitcase is the thing that will not fit / will not go in. That makes it the grammatical subject, so Russian uses the nominative:

• этот чемодан = this suitcase

If it were a direct object instead, its form could change depending on the sentence.

Literally, войдёт comes from войти, which usually means to go in / to enter. But in sentences like this, it often means to fit into.

So:

• не войдёт в багажник = won’t fit in the trunk

This is a very natural Russian way to say that something is too big to go inside a space.

Compare:

• Он вошёл в комнату = He entered the room.
• Стол не войдёт в лифт = The table won’t fit in the elevator.

So the same verb can mean either enter or fit into, depending on context.

Because Russian is talking about a future result.

• входит = is going in / fits / goes in (present, imperfective)
• войдёт = will go in / will fit (future, perfective)

Here the meaning is: This suitcase will not fit in the trunk, so Russian uses the perfective future:

• не войдёт

This is very common in Russian: a perfective verb has no true present tense, so forms like войдёт are future.

A useful contrast:

• Чемодан не входит в багажник. = The suitcase isn’t fitting / doesn’t fit in the trunk.
• Чемодан не войдёт в багажник. = The suitcase won’t fit in the trunk.

Because в can take either accusative or prepositional, depending on the meaning.

Here it shows direction / destination: into the trunk. So Russian uses:

• в + accusative → в багажник

Compare:

• в багажник = into the trunk
• в багажнике = in the trunk

So:

• Чемодан не войдёт в багажник. = The suitcase won’t fit into the trunk.
• Чемодан лежит в багажнике. = The suitcase is in the trunk.

This is a very important Russian pattern:

• куда? where to? → accusative
• где? where? → prepositional

Поэтому means therefore, so, or that’s why.

It links the two ideas:

1. The suitcase won’t fit in the trunk.
2. Therefore, we’ll put it in the passenger compartment.

So the full logic is:

• Этот чемодан не войдёт в багажник, поэтому мы положим его в салон.

The comma is there because Russian is joining two clauses:

• Этот чемодан не войдёт в багажник
• поэтому мы положим его в салон

This comma is normal and expected in Russian.

Положим is the perfective future of положить, meaning we will put / we’ll place.

Russian often prefers the perfective here because it focuses on the completed action/result:

• мы положим его в салон = we’ll put it in the passenger compartment

Compare:

• класть = imperfective, process/repeated action
• положить = perfective, one completed act of putting

So:

• мы положим = we’ll put
• мы будем класть = we will be putting / will put repeatedly or in a process-oriented sense

In this sentence, the speaker means a single practical action, so положим is the natural choice.

Because его is the form used for a direct object here.

The pronoun refers back to чемодан:

• чемодан = the suitcase
• его = it / him

In this sentence, we will put it, so Russian needs the object form, not the subject form:

• он = he/it as subject
• его = him/it as object

So:

• Он не войдёт в багажник. = It won’t fit in the trunk.
• Мы положим его в салон. = We’ll put it in the passenger compartment.

For masculine inanimate nouns like чемодан, его is the normal accusative pronoun.

Here салон means the inside passenger area of the car: the cabin or interior, not the trunk.

So:

• багажник = trunk
• салон = passenger compartment / interior of the car

Thus:

• в салон = into the car interior

This is common vocabulary in Russian when talking about cars.

For the same reason as в багажник: it shows destination, not location.

• в салон = into the interior
• в салоне = in the interior

Here the idea is we will put it into the interior of the car, so Russian uses в + accusative:

• в салон

If the suitcase were already there, you would use:

• Чемодан лежит в салоне. = The suitcase is in the car interior.

Russian word order is fairly flexible, but the original order is very natural.

• Этот чемодан не войдёт в багажник, поэтому мы положим его в салон.

This sounds neutral and clear.

You could rearrange parts for emphasis, for example:

• В багажник этот чемодан не войдёт, поэтому мы положим его в салон.

This emphasizes в багажник.

Or:

• Этот чемодан не войдёт в багажник, поэтому в салон мы положим его.

This is possible, but less neutral and more marked.

So yes, Russian word order can change, but the original sentence is the best everyday version.

Yes: the letter ё matters.

• войдёт is pronounced with yo
• the stress falls on ё

So it sounds roughly like: vay-DYOT

In printed Russian, ё is sometimes written as е, so you may see:

• войдет

But it is still understood and pronounced as войдёт.

For learners, it is helpful to remember that ё is always stressed.