На работе я часто сталкиваюсь с трудными ситуациями.

Yes, на often means on, but in Russian prepositions do not always match English one-to-one.

In На работе, the phrase means at work / at the workplace. This is a very common fixed expression in Russian. So even though the literal pieces look like on work, the natural meaning is at work.

Some similar examples:

• на работе = at work
• на уроке = in class / at the lesson
• на почте = at the post office

So it is best to learn на работе as a set phrase.

Because after на in the sense of location, Russian usually uses the prepositional case.

The noun is:

• работа = work

In the prepositional singular, it becomes:

• на работе = at work

So:

• работа = dictionary form
• на работе = prepositional form after на when talking about being somewhere

Часто means often. It tells you how frequently the action happens.

In this sentence:

• Я часто сталкиваюсь... = I often encounter...

Russian word order is flexible, so часто can move around somewhat, but some positions sound more natural than others.

Common possibilities:

• На работе я часто сталкиваюсь с трудными ситуациями. — very natural
• Я часто сталкиваюсь с трудными ситуациями на работе. — also natural
• Часто на работе я сталкиваюсь с трудными ситуациями. — possible, but with a different emphasis

So the chosen word order is natural and emphasizes at work first, then I often encounter...

Сталкиваюсь comes from the verb сталкиваться с.

It means:

• to encounter
• to come across
• to be faced with

In this sentence, it does not mean a literal physical collision. It is being used figuratively:

• сталкиваться с трудными ситуациями = to encounter difficult situations

This is a very common expression in Russian.

Because the verb is normally used as сталкиваться с кем? с чем? — to encounter / come up against someone or something.

So the structure is:

• сталкиваться с + instrumental case

Examples:

• сталкиваться с проблемами = to encounter problems
• сталкиваться с трудностями = to face difficulties
• сталкиваться с людьми = to come into contact with people

So in your sentence:

• сталкиваюсь с трудными ситуациями

the с is required by the verb.

It is the instrumental plural.

That happens because сталкиваться с requires:

• с + instrumental

The noun is:

• ситуация = situation

Plural:

• ситуации = situations

Instrumental plural:

• ситуациями

The adjective must match the noun:

• трудные ситуации = difficult situations
• с трудными ситуациями = with / encountering difficult situations

So both words are in the instrumental plural:

• трудными
• ситуациями

Because Russian adjectives have to agree with the noun in:

• gender
• number
• case

Here, ситуациями is:

• plural
• instrumental case

So the adjective must also be plural instrumental:

• трудными

Compare:

• трудные ситуации = difficult situations (nominative plural)
• с трудными ситуациями = with difficult situations / encountering difficult situations (instrumental plural)

They are similar, and in many contexts both can mean difficult.

But there is a slight nuance:

• трудный often suggests something hard, challenging, demanding
• сложный often suggests something complex or complicated

So:

• трудные ситуации = difficult situations
• сложные ситуации = complicated situations

Both can work, but трудные ситуации emphasizes difficulty more generally, while сложные ситуации can suggest that the situations are complicated or intricate.

Сталкиваюсь is the 1st person singular present tense form of сталкиваться.

That means:

• я сталкиваюсь = I encounter / I come across

The ending -юсь is used because the verb is reflexive, ending in -ся in its base form:

• сталкиваться

A quick pattern:

• я сталкиваюсь = I encounter
• ты сталкиваешься = you encounter
• он/она сталкивается = he/she encounters
• мы сталкиваемся = we encounter
• вы сталкиваетесь = you encounter
• они сталкиваются = they encounter

Because the sentence describes something that happens repeatedly or habitually:

• я часто сталкиваюсь = I often encounter

For repeated actions, Russian usually uses the imperfective aspect.

• сталкиваться = imperfective
• столкнуться = perfective

Here, часто strongly suggests repetition, so сталкиваюсь is the right choice.

A perfective form would sound more like a single completed encounter, not a regular experience.

Yes, it often can be omitted, because the verb ending already shows the subject:

• сталкиваюсь already means I encounter

So this is also possible:

• На работе часто сталкиваюсь с трудными ситуациями.

However, including я is perfectly natural too. It can make the sentence a bit clearer, more neutral, or slightly more emphatic.

So:

• На работе я часто сталкиваюсь с трудными ситуациями. — natural
• На работе часто сталкиваюсь с трудными ситуациями. — also natural in conversation

Yes, Russian word order is flexible, but different orders create different emphasis.

The original sentence:

• На работе я часто сталкиваюсь с трудными ситуациями.

This naturally highlights at work first.

Other possible versions:

• Я часто сталкиваюсь с трудными ситуациями на работе. — more neutral if you start with I
• С трудными ситуациями я часто сталкиваюсь на работе. — emphasizes difficult situations
• Часто на работе я сталкиваюсь с трудными ситуациями. — emphasizes often

So the meaning stays similar, but the focus shifts.

The main stresses are:

• на рабо́те
• я ча́сто
• сталкива́юсь
• с тру́дными
• ситуа́циями

A rough pronunciation guide for an English speaker:

• На работе ≈ na ra-BO-tye
• я часто ≈ ya CHAS-ta
• сталкиваюсь ≈ stal-kee-VA-yus
• с трудными ситуациями ≈ s TRUD-ny-mi si-too-A-tsi-ya-mi

The hardest word for many learners is сталкиваюсь, so it helps to say it slowly first:

• стал-ки-ва-юсь

Yes, absolutely. That is a very natural English translation.

Depending on context, сталкиваюсь с трудными ситуациями can be translated as:

• I often encounter difficult situations
• I often face difficult situations
• I often deal with difficult situations
• I often come across difficult situations

The Russian wording is slightly closer to encounter / face, but deal with is often a very natural English equivalent.