Kê khai thời hạn sử dụng khi cấp đổi.

Kê khai is a formal, administrative verb meaning to declare, list, report, or fill in information on a form.

Compared with khai, kê khai sounds more bureaucratic and is especially common in official paperwork. In this sentence, it suggests that the person must state or provide the validity information as part of an application or record.

So yes, it is related to khai, but kê khai is more formal and document-focused.

Literally:

• thời hạn = time limit / period
• sử dụng = use

So thời hạn sử dụng literally means the period during which something may be used.

In practical English, it often means:

• validity period
• expiration period
• sometimes expiry date, depending on context

In official Vietnamese, this phrase is often used for documents, permits, cards, products, or anything that has a limited valid/use period.

That is a very natural question for an English speaker.

In Vietnamese, sử dụng does literally mean to use, but in phrases like thời hạn sử dụng, it often refers to the time something remains usable or valid.

So the phrase does not necessarily focus on physical use. In administrative or legal language, it can mean something closer to:

• how long it is valid
• how long it can legally be used

That is why the English meaning may sound more like validity period than just period of use.

Khi means when.

Cấp đổi is an official administrative expression meaning something like:

• to reissue by exchange
• to renew and replace
• to issue a replacement document

So khi cấp đổi means when reissuing, during renewal/replacement, or in the process of exchanging for a new document/item.

This is common in government and paperwork contexts, especially for licenses, certificates, cards, and permits.

It is best understood as a set administrative phrase.

• cấp = issue
• đổi = change / exchange / replace

Together, cấp đổi has a specialized meaning in official language: to issue a replacement/renewed version in exchange for an old one.

So even though it is written as two words, learners should treat it as a fixed expression.

Because this is typical instructional or administrative Vietnamese.

Vietnamese often omits the subject when it is obvious from context, especially in:

• instructions
• notices
• forms
• regulations
• bullet points

So Kê khai thời hạn sử dụng khi cấp đổi is not a full conversational sentence like You must declare the validity period when renewing. Instead, it is more like a brief official instruction:

• Declare the validity period upon renewal
• State the validity period when applying for reissuance

This kind of subject omission is very common.

It is more like a short official instruction than a fully complete everyday sentence.

In natural English, it feels like a heading, form instruction, or procedural note. Vietnamese administrative style often uses short verb phrases like this without extra words.

So grammatically, it functions more like:

• Declare the validity period when renewing
• Provide the validity period upon reissuance

rather than a full spoken sentence with a subject.

The structure is:

• Kê khai = declare / provide
• thời hạn sử dụng = validity period
• khi cấp đổi = when reissuing / upon renewal

So the order is basically:

Verb + object + time/situation clause

A very literal breakdown would be:

• Declare
• the validity period
• when reissuing

That word order is very normal in Vietnamese.

Yes.

Khi usually means when, but in formal translation, upon or during may sound more natural depending on context.

So khi cấp đổi could be rendered as:

• when reissuing
• upon renewal/reissuance
• during the replacement process

In official English, upon often matches the formal tone better, but when is the basic meaning.

They are closely related, but not always identical in tone.

• hạn sử dụng often means expiry date or expiration limit, especially on products
• thời hạn sử dụng is slightly fuller and can sound more formal, emphasizing the period of validity/use

In many contexts, they overlap. But thời hạn sử dụng can sound a bit more administrative or formal, which fits this sentence.

Not usually.

This sentence is strongly bureaucratic and official-sounding. You are much more likely to see it in:

• forms
• instructions
• regulations
• application procedures
• government paperwork

In everyday conversation, a speaker would probably use a fuller and more natural sentence, depending on the situation.

Yes, and that is a useful distinction to learn.

In administrative language:

• cấp lại = reissue again, often because something was lost, damaged, or needs to be reissued
• cấp đổi = reissue by exchange/replacement, often when changing from an old version to a new one

The exact distinction depends on the document and regulations, but generally cấp đổi implies replacement or exchange, not just issuing again for any reason.

It is very formal and specifically administrative.

Words like kê khai and cấp đổi are strong signals of official written Vietnamese. A learner should recognize that this is not casual speech, but the language of:

• institutions
• legal procedures
• public administration
• formal documentation

So this is useful vocabulary, but mainly for dealing with paperwork rather than daily conversation.

A rough pronunciation guide:

• kê khai → kay khai
• thời hạn sử dụng → thuh-ee han suu zoong in northern pronunciation, though exact English-style approximations are imperfect
• khi cấp đổi → khee cup doy

Important tone notes:

• kê has a level tone
• khai has a level tone
• thời has a falling-rising tone
• hạn has a heavy low tone
• sử has a broken rising tone
• dụng has a heavy low tone
• cấp has a sharp rising tone
• đổi has a dipping-rising tone

Since tones matter a lot in Vietnamese, it helps to learn this sentence by listening to native audio rather than relying only on English-style approximations.