Tôi kiểm tra giao dịch và phí rồi nhập mã PIN.

Here, rồi links two actions in sequence: check the transaction and fee(s), then enter the PIN.

In this sentence, rồi is best understood as then / after that / and then.

So:

• Tôi kiểm tra giao dịch và phí rồi nhập mã PIN.
• I check the transaction and fee(s), then enter the PIN.

A useful point: rồi does not always mean past tense. It can mean already in other sentences, but here it mainly shows the order of actions.

Vietnamese often avoids repeating the subject when it is already clear.

So instead of saying:

• Tôi kiểm tra giao dịch và phí rồi tôi nhập mã PIN.

Vietnamese more naturally says:

• Tôi kiểm tra giao dịch và phí rồi nhập mã PIN.

The subject tôi still applies to both verbs:

• tôi kiểm tra ...
• (tôi) nhập ...

This is very common in Vietnamese.

Yes. Kiểm tra means to check, inspect, verify, review depending on context.

In this sentence, kiểm tra giao dịch và phí means something like:

• check/review the transaction and the fee(s)

Compared with some other verbs:

• kiểm tra = check carefully, verify
• xem = look at, view, take a look
• xác nhận = confirm

So kiểm tra is a good choice if you mean checking details before doing the next step.

• giao dịch = transaction
• phí = fee, charge

So giao dịch và phí means the transaction and the fee(s)/charges.

A learner may expect words like the or plural -s, but Vietnamese usually does not mark those things the same way English does.

That means:

• giao dịch can mean transaction or transactions, depending on context
• phí can mean fee or fees

The context tells you what is meant.

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

So where English says:

• the transaction
• the fee
• the PIN

Vietnamese often just says:

• giao dịch
• phí
• mã PIN

If the speaker needs to be more specific, Vietnamese can add other words, but very often the noun alone is enough.

Literally:

• nhập = enter / input
• mã PIN = PIN code

So nhập mã PIN means enter the PIN.

A small note:

• mã means code
• PIN is the borrowed English abbreviation

So literally it is something like enter the PIN code.

In normal usage, this is completely natural, especially in technical, banking, or ATM-related language.

This is similar to expressions in English like PIN number or ATM machine, where part of the meaning is technically repeated.

In Vietnamese, mã PIN is very common and natural. The word mã helps make it clear that this is a code.

So even if it feels redundant from a strict English point of view, it is standard everyday usage.

Mostly yes. The basic order here is:

• Tôi = I
• kiểm tra = check
• giao dịch và phí = the transaction and fee(s)
• rồi = then
• nhập mã PIN = enter the PIN

So Vietnamese is following a pattern that feels familiar to English speakers:

Subject + Verb + Object + then + Verb + Object

That is one reason this sentence is relatively easy for English speakers to follow.

Yes, in the right context.

If it is already obvious who is doing the actions, Vietnamese can drop tôi:

• Kiểm tra giao dịch và phí rồi nhập mã PIN.

This can sound like:

• an instruction
• a note in a process
• a casual statement where the subject is understood

But if you want to clearly say I, especially in a standalone sentence, keeping tôi is helpful.

Yes, it sounds natural in a banking, payment, or ATM-type context.

It describes a sequence of actions clearly:

1. check the transaction and fee(s)
2. enter the PIN

The vocabulary is practical and standard:

• giao dịch = transaction
• phí = fee
• mã PIN = PIN code

So this is the kind of sentence you might see in instructions, app steps, or descriptions of what someone does during a payment process.

A rough learner-friendly guide:

• giao dịch
  • giao sounds roughly like zow in northern Vietnamese, and often more like yow in southern Vietnamese
  • dịch has a short ending and a heavy tone
• phí
  • sounds a bit like fee, but with a Vietnamese tone
• nhập
  • starts with nh, which is somewhat like the ny sound in canyon for many learners
  • ends with a short p stop

The exact pronunciation depends on accent, especially North vs South, but the spelling gives you the core word shapes. If you are learning pronunciation, nhập is the trickiest word here for most English speakers.