Thủ thư kiểm tra cả thẻ và mã vạch.

Thủ thư means librarian.

It is written as two separate syllables/words in Vietnamese spelling, but together they form one fixed expression with one meaning.

A useful comparison:

• thư viện = library
• thủ thư = librarian

So even though they look similar, thư viện and thủ thư are different words with different meanings.

The sentence follows the very common Vietnamese pattern:

Subject + Verb + Object

So here:

• Thủ thư = subject
• kiểm tra = verb
• cả thẻ và mã vạch = object phrase

This is similar to English word order:

• The librarian
  • checks
    • both the card and the barcode

Vietnamese does not use articles like a / an / the the way English does.

So:

• thủ thư can mean a librarian or the librarian
• thẻ can mean a card or the card
• mã vạch can mean a barcode or the barcode

The exact meaning depends on context.

In this sentence, English naturally uses the librarian, the card, and the barcode, but Vietnamese usually leaves that unstated unless it needs to be more specific.

Kiểm tra means to check, to inspect, or to examine.

In this sentence, kiểm tra means the librarian is checking something.

Examples:

• kiểm tra thẻ = check the card
• kiểm tra mã vạch = check the barcode

It is a very common verb in Vietnamese.

Cả here gives the meaning of both.

So:

• thẻ và mã vạch = the card and the barcode
• cả thẻ và mã vạch = both the card and the barcode

It emphasizes that both items are being checked, not just one of them.

A very useful pattern is:

cả A và B = both A and B

So in your sentence:

• cả thẻ và mã vạch = both the card and the barcode

Yes.

Without cả, you get:

Thủ thư kiểm tra thẻ và mã vạch.

That still means:

• The librarian checks the card and the barcode

But it is a little less emphatic. It simply lists two things.
Adding cả makes it clearer that both are included.

So:

• thẻ và mã vạch = card and barcode
• cả thẻ và mã vạch = both the card and the barcode

Because the standard Vietnamese pattern is:

cả + item 1 + và + item 2

Examples:

• cả anh và tôi = both you and I
• cả sách và báo = both books and newspapers
• cả thẻ và mã vạch = both the card and the barcode

So cả introduces the whole pair, and và connects the two items.

Thẻ is a general word meaning card, pass, tag, or sometimes ID-type card, depending on context.

In this sentence, it most naturally means some kind of library card or membership card, because the subject is the librarian.

Vietnamese often leaves this kind of detail implicit if the context makes it obvious.

So:

• thẻ by itself = card
• in this context = probably library card

Mã vạch means barcode.

Literally:

• mã = code
• vạch = line / stripe

So the idea is basically a code made of lines.

This is a fixed common term in Vietnamese:

• mã vạch = barcode

Because Vietnamese writing usually separates syllables with spaces, even when they function together as one vocabulary item.

So mã vạch is written as two written units, but it works as one lexical expression meaning barcode.

This is very common in Vietnamese. For example:

• thủ thư = librarian
• thư viện = library
• mã vạch = barcode

So do not assume that a space always means the same thing it does in English.

No, not in this sentence.

Classifiers are common in Vietnamese, but they are not required in every noun phrase. Here, the nouns are being mentioned directly as objects of the verb, so thẻ and mã vạch can appear without classifiers.

You might see classifiers in other contexts, especially when counting or specifying:

• một cái thẻ = a card
• một mã vạch = a barcode

But in your sentence, the simpler form is completely natural:

• kiểm tra cả thẻ và mã vạch

Vietnamese verbs do not change form the way English verbs do.
The sentence Thủ thư kiểm tra cả thẻ và mã vạch can mean:

• The librarian checks both the card and the barcode
• The librarian is checking both the card and the barcode

The exact tense/aspect depends on context.

If you want to make the ongoing action clearer, you can add đang:

• Thủ thư đang kiểm tra cả thẻ và mã vạch.
• The librarian is checking both the card and the barcode.

A rough learner-friendly breakdown is:

• Thủ thư
• kiểm tra
• cả thẻ và mã vạch

Things to watch:

• Vietnamese is tonal, so the tones matter a lot.
• thủ and thẻ do not have the same tone.
• mã and vạch also have different tones.

It is best to learn pronunciation from audio, but a slow chunking strategy helps:

1. thủ thư
2. kiểm tra
3. cả thẻ và mã vạch

Then say the whole sentence smoothly.

Not very naturally.

A word-for-word gloss would be something like:

• thủ thư = librarian
• kiểm tra = check
• cả = both
• thẻ = card
• và = and
• mã vạch = barcode

But natural English needs articles and verb agreement:

• The librarian checks both the card and the barcode.

So Vietnamese and English match fairly well here in word order, but not perfectly in grammar.