Tôi hỏi về trách nhiệm và phúc lợi.

Because hỏi về means to ask about.

• hỏi = to ask
• về = about

So:

• Tôi hỏi về trách nhiệm và phúc lợi = I ask / asked about responsibilities and benefits.

Without về, hỏi usually needs a direct object such as a person or a question:

• Tôi hỏi anh ấy. = I ask/asked him.
• Tôi hỏi một câu. = I ask/asked a question.

When you want to introduce the topic you are asking about, về is very common.

The sentence follows a very normal Vietnamese pattern:

• Tôi = subject
• hỏi = verb
• về trách nhiệm và phúc lợi = prepositional phrase showing the topic

So the structure is:

Subject + Verb + về + Topic

That is why the sentence is:

Tôi hỏi về trách nhiệm và phúc lợi.

This is fairly close to English I ask about responsibilities and benefits.

By itself, hỏi does not show tense. Vietnamese verbs do not change form the way English verbs do.

So Tôi hỏi về trách nhiệm và phúc lợi could mean:

• I ask about responsibilities and benefits
• I asked about responsibilities and benefits

The exact time depends on context, or on time words added to the sentence.

Examples:

• Hôm qua tôi hỏi về trách nhiệm và phúc lợi. = Yesterday I asked about responsibilities and benefits.
• Bây giờ tôi hỏi về trách nhiệm và phúc lợi. = Now I’m asking about responsibilities and benefits.

Sometimes yes, if the subject is already obvious from context.

For example, in conversation, a speaker might say simply:

• Hỏi về trách nhiệm và phúc lợi.

But this sounds more fragment-like and depends heavily on context. As a full, clear sentence for learners, Tôi hỏi về trách nhiệm và phúc lợi is better.

Also, tôi is a neutral, common way to say I, especially in formal or careful speech.

They are both fairly formal vocabulary items.

• trách nhiệm = responsibility, responsibilities
• phúc lợi = welfare, benefits, employee benefits

In a work context:

• trách nhiệm often means job responsibilities or duties
• phúc lợi often refers to benefits such as insurance, paid leave, allowances, and similar things

So this sentence sounds natural in a professional setting, such as discussing a job.

Yes, it is understandable and fairly natural, especially in a formal or written style.

However, in real conversation, a speaker might make it more specific:

• Tôi hỏi về trách nhiệm công việc và phúc lợi. = I asked about job responsibilities and benefits.
• Tôi muốn hỏi về trách nhiệm công việc và phúc lợi. = I’d like to ask about job responsibilities and benefits.

The version with muốn hỏi often sounds a little softer and more polite in real-life conversation.

Vietnamese usually does not mark singular/plural the same way English does. Nouns often stay the same whether they are singular or plural.

So:

• trách nhiệm can mean responsibility or responsibilities
• phúc lợi can mean benefit or benefits

Context tells you whether the meaning is singular or plural. In this sentence, English would usually translate them as plurals because that sounds more natural.

Yes, in this sentence và works like and:

• trách nhiệm và phúc lợi = responsibilities and benefits

It simply links two nouns.

In casual spoken Vietnamese, people sometimes use other ways of linking ideas, but và is the standard, straightforward choice and is very common in writing and formal speech.

A few pronunciation notes:

• tôi: the ôi sound is somewhat like the vowel combination in English boy, but not exactly the same.
• hỏi: this has the hỏi tone, which is one of the trickier Vietnamese tones for English speakers. The voice typically dips and then rises.
• trách nhiệm:
  • trách starts with tr, which many learners find difficult
  • nhiệm also has a tone and a consonant cluster that may take practice

Also remember that standard Vietnamese is tonal, so correct tones matter a lot. Even if your consonants are good, incorrect tones can make the word hard to understand.

It is not the best choice if you mean ask about responsibilities and benefits.

Using về makes the relationship clear:

• Tôi hỏi về trách nhiệm và phúc lợi.

Without về, the sentence sounds incomplete or unnatural to many speakers, because trách nhiệm và phúc lợi are topics, not the person being asked.

So for this meaning, keep về.

You can add the person after hỏi, then keep về for the topic.

Pattern:

Tôi hỏi + person + về + topic

Example:

• Tôi hỏi nhà tuyển dụng về trách nhiệm và phúc lợi. = I asked the recruiter about responsibilities and benefits.
• Tôi hỏi anh ấy về trách nhiệm và phúc lợi. = I asked him about responsibilities and benefits.

That is a very common structure in Vietnamese.