Ben kasada nakit olarak ödeme yapacağım.

Yes. In Turkish, subject pronouns are often omitted because the verb ending already shows the subject.

• yapacağım = I will do / I will make
• So Ben kasada nakit olarak ödeme yapacağım can simply be Kasada nakit olarak ödeme yapacağım.

Including Ben adds emphasis, contrast, or clarity, like:

• I will pay in cash.
• As for me, I’ll pay at the register in cash.

So Ben is grammatical, but not always necessary.

Kasada means at the cash register / at the checkout / at the till.

It comes from:

• kasa = cash register, till, checkout point
• -da = the locative ending, meaning in / at / on

So:

• kasa → kasada = at the register

In a store or supermarket context, this is a very natural expression.

The suffix -da / -de / -ta / -te is the Turkish locative suffix, used to mean in, at, on.

Here:

• kasa ends in a vowel and contains the back vowel a
• so the correct form is -da
• kasa + da = kasada

Some examples:

• evde = at home
• okulda = at school
• masada = on the table
• kasada = at the checkout

So kasada tells you the location where the payment happens.

Nakit olarak means in cash or more literally as cash / in the form of cash.

• nakit = cash
• olarak = as, in the role/form of

So:

• nakit olarak ödeme yapmak = to make a payment in cash

In Turkish, olarak is often used to express in the form of, as, or by way of.

That said, in everyday speech, people may also say:

• Nakit ödeyeceğim.
• Kasada nakit ödeyeceğim.

These are also natural. Nakit olarak ödeme yapacağım sounds a bit fuller and slightly more formal.

Both are possible.

• ödemek = to pay
• ödeme yapmak = to make a payment

Turkish often uses a noun + light verb structure, where a noun combines with a common verb like yapmak or etmek.

Here:

• ödeme = payment
• yapmak = to do / to make
• ödeme yapmak = to make a payment

So this sentence could also be:

• Ben kasada nakit olarak ödeyeceğim.

That version is a little shorter and more direct.
Ödeme yapacağım can sound slightly more formal, careful, or transactional.

Yapacağım comes from the verb yapmak (to do / to make).

Breakdown:

• yap- = verb stem
• -acak / -ecek = future tense
• -ım / -im / -um / -üm = I ending

So in theory:

• yap + acak + ım

But Turkish sound changes make it:

• yapacağım

A useful thing to notice is that the k in -acak often softens to ğ before a vowel in these forms:

• yapacak = he/she/it will do
• yapacağım = I will do

So ödeme yapacağım literally means I will make a payment.

Because Turkish normally puts the main verb at the end.

So the sentence structure is roughly:

• Ben = I
• kasada = at the checkout
• nakit olarak = in cash
• ödeme yapacağım = will make a payment

This end-position for the verb is one of the most basic features of Turkish word order.

English: I will pay in cash at the checkout.
Turkish: I at the checkout in cash payment will make.

That literal word-for-word order sounds strange in English, but it is normal in Turkish.

Yes. Turkish word order is flexible, although some orders sound more natural in certain contexts.

The original sentence:

• Ben kasada nakit olarak ödeme yapacağım.

Other possible versions:

• Kasada nakit olarak ödeme yapacağım.
• Nakit olarak kasada ödeme yapacağım.
• Ödeme yapacağım kasada, nakit olarak. (more marked, context-dependent)

The final position often gets special focus, so changing word order can change emphasis.

For learners, the original order is a safe and natural choice.

Yes, absolutely.

• Ben kasada nakit ödeyeceğim. = I’ll pay cash at the checkout.
• Ben kasada nakit olarak ödeme yapacağım. = I’ll make the payment in cash at the checkout.

The first is shorter and more conversational.
The second is a bit more explicit and slightly more formal.

Both are correct.

Yes. Yapacağım is straightforward future tense: I will do / I am going to do.

In context, it can express:

• a future action
• an intention
• a decision

So this sentence can feel like:

• I will pay in cash
• I’m going to pay in cash

Turkish future tense often covers both ideas naturally.

Yes, it is natural and correct, especially in a clear transactional context.

That said, in everyday speech, people might often use a shorter version such as:

• Kasada nakit ödeyeceğim.
• Nakit ödeyeceğim.
• Ödemeyi kasada nakit yapacağım.

Your sentence sounds complete, clear, and perfectly understandable. It may feel a little more formal than the shortest everyday options, but it is definitely good Turkish.