jiěguà yǐhòu, qǐng bǎocún jiāoyìpíngzhèng, zài kàn yínhángkǎ de yǒuxiàoqī.

The subject is omitted because it is understood from context.

In Chinese, it is very common to leave out you, I, we, etc. when they are obvious. In a bank instruction like this, the implied subject is usually you.

So the sentence is understood as:

After unblocking/canceling the hold, please keep the transaction receipt, then check the bank card’s expiration date.

Chinese often sounds more natural this way than if it explicitly said 你.

以后 means after or afterwards.

When it follows a verb or verb phrase, it creates a time phrase:

• 解挂以后 = after unblocking / after removing the hold

So the structure is:

Verb phrase + 以后 = after doing ...

Examples:

• 吃饭以后 = after eating
• 下班以后 = after getting off work
• 付款以后 = after paying

Here, 解挂以后 sets the time for the rest of the sentence.

请 makes the instruction polite. It often corresponds to please in English.

So:

• 请保存交易凭证 = please keep/save the transaction receipt

Without 请, the sentence would sound more direct, like a plain command. In service, banking, and official instructions, 请 is very common because it sounds courteous and professional.

Here, 再 means then / after that / next, not necessarily again.

In this sentence:

• 请保存交易凭证，再看银行卡的有效期
• Please keep the transaction receipt, then check the card’s expiration date

So 再 marks the next step in a sequence.

This is a very common use in instructions:

• 先付款，再取票 = first pay, then pick up the ticket
• 先保存，再关闭页面 = first save, then close the page

Although 再 can sometimes mean again, in this sentence it is clearly about doing the next action.

This is a very common learner question.

In simple terms:

• 再 is often used for something that happens afterward or one more time in the future
• 又 is often used for something that has already happened again

Here the sentence is giving instructions in order, so 再 is the natural choice:

• 先……，再…… = first..., then...

If you used 又 here, it would sound wrong, because the sentence is not saying the person is checking the card again after already checking it before. It is just giving the next step.

In everyday Chinese, 看 often means more than just physically look at. It can also mean:

• check
• inspect
• have a look at

So:

• 看银行卡的有效期 means check the bank card’s expiration date

This is very natural Chinese. Even though English might prefer check, Chinese often uses 看 in practical instructions.

Compare:

• 看一下身份证 = check the ID
• 看时间 = check the time
• 看看有没有问题 = check whether there is a problem

的 links a modifier to a noun.

Here:

• 银行卡 = bank card
• 有效期 = validity period / expiration date
• 银行卡的有效期 = the bank card’s validity period / the expiration date of the bank card

So 的 is functioning a bit like ’s or of in English.

This is a very common pattern:

• 我的名字 = my name
• 公司的地址 = the company’s address
• 护照的号码 = the passport number

Yes. Both are possible, but they sound different in English.

Literally, 有效期 is validity period. But in natural English, when talking about bank cards, people usually say:

• expiration date
• sometimes expiry date

So in real translation, check the bank card’s expiration date sounds more natural than check the bank card’s validity period, even though the Chinese wording is more literally validity period.

It is best understood as a fixed noun phrase or compound noun.

• 交易 = transaction
• 凭证 = voucher, receipt, proof document

Together:

• 交易凭证 = transaction receipt / transaction voucher / proof of transaction

In this sentence, it is the object of 保存:

• 保存交易凭证 = keep/save the transaction receipt

In banking or formal contexts, 凭证 often refers to some document that serves as official proof.

Here 保存 means keep, retain, or save/preserve.

In this context, it means you should keep the transaction receipt instead of throwing it away.

保存 is often used for:

• saving files
• preserving documents
• keeping records
• storing things carefully

Examples:

• 保存文件 = save a file
• 保存证据 = preserve evidence
• 保存好收据 = keep the receipt safely

So in this sentence, 保存 is a formal and appropriate word.

Yes. 解挂后 and 解挂以后 are both possible.

• 后 = after
• 以后 = after / afterwards

In many sentences, they are very similar.

So these both work:

• 解挂后，请保存交易凭证
• 解挂以后，请保存交易凭证

Sometimes 以后 feels a little fuller or slightly more explicit, while 后 feels a bit shorter and more compact. But in this kind of instruction, both are natural.

The commas separate steps and make the instruction easier to read.

The sentence has a step-by-step structure:

1. 解挂以后
2. 请保存交易凭证
3. 再看银行卡的有效期

Chinese punctuation often helps show the flow of actions, especially in formal instructions.

So the commas are not random—they divide the sentence into logical parts:

• time condition first
• first action
• next action

It follows a very common Chinese instruction pattern:

[After doing X], please do Y, then do Z.

In this sentence:

• 解挂以后 = after doing X
• 请保存交易凭证 = please do Y
• 再看银行卡的有效期 = then do Z

Chinese often presents actions in the order they happen. This makes the sentence very clear and natural.

So the grammar is not complicated once you see the pattern:

• time phrase first
• main action
• next action

That word order is one of the most important things to get used to in Chinese.