Таможенник попросил меня открыть чемодан.

Попросил is the past-tense form of попросить. In Russian, past tense agrees with the subject in gender and number.

Here, таможенник is masculine singular, so the verb is попросил.

Compare:

• таможенник попросил = a male customs officer asked
• таможенница попросила = a female customs officer asked
• таможенники попросили = customs officers asked

So the -л past-tense form here tells you the subject is masculine singular.

Because меня is the accusative form of я.

In this sentence, меня is the person being asked, so it is the direct object of попросил.

• я = I
• меня = me

So:

• Таможенник попросил меня... = The customs officer asked me...

This is a very common Russian pattern: попросить + кого? + infinitive
That means to ask someone to do something.

Because Russian uses the pattern:

попросить + someone + infinitive

So попросил меня открыть чемодан literally follows the structure:

asked me open suitcase

English needs to before the infinitive: asked me to open the suitcase.
Russian does not use a separate word like to here. The infinitive form itself is enough.

This is a question of aspect.

• открыть = perfective, to open once / to complete the action
• открывать = imperfective, to be opening / to open repeatedly / to focus on the process

In this sentence, the customs officer asked for one completed action: open the suitcase. That is why открыть is the natural choice.

If you used открывать, it would sound more like focusing on the process or repeated action, which is not the usual meaning here.

It actually is in the accusative case, but for an inanimate masculine singular noun, the accusative form is the same as the nominative.

So:

• nominative: чемодан
• accusative: чемодан

Since чемодан is the direct object of открыть, it must be accusative. It just happens to look unchanged.

Compare with an animate masculine noun:

• я вижу брата = I see my brother

There the accusative looks different.

The sentence follows this structure:

[subject] + [verb] + [person asked] + [infinitive] + [object]

So here:

• Таможенник = subject
• попросил = verb
• меня = person who was asked
• открыть = infinitive
• чемодан = object of that infinitive

This is a very useful pattern to learn, because it works with many similar sentences:

• Он попросил меня подождать. = He asked me to wait.
• Она попросила нас помочь. = She asked us to help.

No, Russian word order is fairly flexible, although this version is the most neutral and natural.

Таможенник попросил меня открыть чемодан is the standard order.

You may also hear other orders for emphasis, for example:

• Меня таможенник попросил открыть чемодан.
• Открыть чемодан меня попросил таможенник.

These do not usually change the core meaning, but they change what is emphasized or what sounds most natural in context.

For learners, the given word order is the safest default.

There is no separate word for English to here.

Russian uses the infinitive directly:

• открыть = to open

So попросил меня открыть already means asked me to open.

This is normal in Russian:

• велел мне уйти = told me to leave
• заставил меня ждать = made me wait
• попросил меня помочь = asked me to help

Russian does not have articles like a or the.

So:

• таможенник can mean a customs officer or the customs officer
• чемодан can mean a suitcase or the suitcase

The exact meaning comes from context, not from an article.

In this sentence, English naturally uses the customs officer and the suitcase, but Russian does not need separate words for that.

Yes. They are related, but they differ in aspect.

• просить = imperfective
• попросить = perfective

In many contexts:

• просил can suggest the act of asking as a process, repeated action, or something not viewed as completed
• попросил presents the request as a single completed event

Here, попросил fits well because the sentence describes one specific request made by the customs officer.

The stress is:

• тамо́женник
• попроси́л
• меня́
• откры́ть
• чемода́н

So the sentence is pronounced approximately as:

тамо́женник попроси́л меня́ откры́ть чемода́н

For a learner, the most important thing is to remember the stressed syllables, because Russian vowel pronunciation changes a lot when vowels are unstressed.

That is close to the Russian structure, but not natural English.

A more literal breakdown is:

• Таможенник = customs officer
• попросил = asked
• меня = me
• открыть = to open
• чемодан = suitcase

So the natural English translation is:

The customs officer asked me to open the suitcase.

Literal breakdowns can help you understand Russian grammar, but they often should not be copied directly into English.