Перед выходом из дома я всегда проверяю, есть ли у меня проездной.

Выходом is the instrumental singular of выход.

The preposition перед usually takes the instrumental case when it means before or in front of.

So:

• перед выходом = before leaving / before going out
• literally: before the exit / before the act of going out

This is a very common Russian pattern:

• перед сном = before sleep / before going to bed
• перед уроком = before class
• перед работой = before work

In this sentence, выход is being used as a noun, so instead of saying before I leave the house, Russian says something like before the leaving from the house.

After из (out of / from), Russian uses the genitive case.

So:

• дом = house, home
• из дома = out of the house / from home

Here, дома is the genitive singular form of дом.

Be careful: дома can also mean at home, but that is a different use.

Compare:

• Я дома. = I am at home.
• Я выхожу из дома. = I’m leaving home.

In your sentence, because it follows из, it is definitely the genitive form: out of the house / from home.

Russian often uses a noun phrase where English prefers a clause.

So:

• перед выходом из дома literally = before the leaving from home
• natural English = before leaving the house / before I leave home

This is a very normal and natural Russian structure. Russian likes turning actions into nouns in expressions like this.

Another very common way to say it would be:

• Перед тем как выйти из дома, ... = Before leaving the house, ...

Both are correct. The version with перед выходом is a bit more compact and formal-neutral.

Проверяю is the 1st person singular present of the imperfective verb проверять.

Russian uses the imperfective here because this is a habitual / repeated action:

• я всегда проверяю = I always check

The sentence is not about one completed checking event. It is about something the speaker does regularly.

Compare:

• Я всегда проверяю = I always check.
• Я проверю = I will check / I’ll check once.

So the imperfective is exactly what you expect for always, usually, often, etc.

Есть ли means whether there is / if there is in an indirect yes/no question.

The phrase:

• проверяю, есть ли у меня проездной

means:

• I check whether I have my travel pass
• more literally: I check whether there is a travel pass with me / in my possession

In Russian, ли is used to form indirect yes/no questions.

Examples:

• Я не знаю, дома ли он. = I don’t know whether he is at home.
• Спроси, придёт ли она. = Ask whether she will come.
• Проверь, есть ли билет. = Check whether there is a ticket.

So here есть ли introduces the idea whether I have one.

In Russian, ли usually comes right after the word that is being questioned or focused.

Here the basic idea is:

• Есть у меня проездной? = Do I have a travel pass?

When this becomes an indirect question, it turns into:

• ...есть ли у меня проездной = ...whether I have a travel pass

So ли follows есть.

This is one of the most important things to remember about ли: it does not usually go at the beginning the way English uses if/whether.

More examples:

• Я не знаю, будет ли дождь. = I don’t know whether it will rain.
• Спроси, можно ли войти. = Ask whether it is possible to come in.
• Интересно, прав ли он. = I wonder whether he is right.

Russian usually expresses possession with the structure:

• у + genitive + есть

So:

• у меня есть проездной = I have a travel pass
• literally: by me there is a travel pass

This is the normal way to say have in Russian.

So in your sentence:

• есть ли у меня проездной = whether I have a travel pass

Here:

• я → nominative = I
• меня → genitive after у
• у меня = in my possession / with me

Russian does have verbs that can sometimes express possession, but for ordinary I have / do you have / she has, this у кого-то есть что-то pattern is the standard one.

Проездной is short for проездной билет.

Originally, проездной is an adjective meaning something like valid for travel / travel-related, but in everyday Russian it is often used on its own as a noun:

• проездной = travel pass / transit pass

This is very common in Russian: an adjective can stand alone when the noun is understood.

Other examples:

• столовая = dining room / cafeteria, originally from an adjective
• выходной = day off
• мороженое = ice cream

So проездной by itself is perfectly natural.

The comma separates the main clause from the subordinate clause.

Main clause:

• я всегда проверяю = I always check

Subordinate clause:

• есть ли у меня проездной = whether I have a travel pass

Russian uses commas very consistently to separate clauses, including indirect-question clauses like this one.

So the comma is required:

• Я проверяю, есть ли...

Just as in English you might write:

• I check whether I have my pass.

English does not require a comma there, but Russian does.

Yes, Russian word order is flexible, but the given order is very natural:

• я всегда проверяю = I always check

You could also hear:

• я проверяю всегда
• всегда я проверяю

But those would sound different in emphasis or less neutral in many contexts.

The sentence as written is neutral and natural:

• Перед выходом из дома я всегда проверяю...

Also, putting перед выходом из дома at the beginning sets the time frame first, which is very common in Russian.

So the order is not random; it is the most standard, smooth way to say it.

Usually, no. In this sentence, ли is the correct word.

Russian ли is used for whether in indirect yes/no questions:

• проверяю, есть ли у меня проездной = I check whether I have my travel pass

Если usually means if in the sense of a condition:

• Если у меня есть проездной, я еду на метро. = If I have a travel pass, I go by metro.

So:

• ли = whether
• если = if, in a conditional sense

English uses if for both meanings, but Russian normally keeps them separate.

In Russian, there are no articles, so проездной by itself could literally be a travel pass or the travel pass, depending on context.

In this sentence, the real meaning is clearly my travel pass, because the speaker is checking whether they have it with them before leaving.

So although Russian says just:

• есть ли у меня проездной

English naturally understands:

• whether I have my travel pass

This is a good example of how Russian relies on context instead of articles like a and the.

Not naturally in this sentence.

Russian sometimes omits есть in the present tense, but not in this possession pattern when you are explicitly asking whether something exists in someone’s possession.

So:

• У меня есть проездной. = I have a travel pass.
• Есть ли у меня проездной? = Do I have a travel pass?

Without есть, the sentence would sound wrong or incomplete here.

So in this construction, есть is important.

Проездной is in the nominative singular.

That is because in the construction у меня есть X, the thing possessed is normally in the nominative:

• У меня есть билет.
• У меня есть паспорт.
• У меня есть проездной.

So:

• у меня = genitive after у
• проездной = nominative, as the thing that is present / exists

This feels strange to English speakers at first, because English thinks in terms of I have X, where I is the subject. Russian instead structures it more like With me there exists X, so X stays nominative.

It is neutral, standard Russian.

Nothing in it is especially formal or especially casual.

• Перед выходом из дома sounds natural and slightly tidy in style.
• проверяю is ordinary everyday language.
• проездной is a normal everyday word.

So this is the kind of sentence you could say in conversation, write in a textbook, or use as a general statement about your routine.