Learn Hardcore Japanese: sono apuri ha oturi no keisan mo dekiru.

It marks the topic. そのアプリは means “as for that app.” It sets “that app” as the thing we’re talking about; the rest (お釣りの計算もできる) says something about it. Using は here is natural when describing an app’s features.

What nuance does も add in 計算も?

も means “also/as well.” お釣りの計算もできる implies the app can do other things, and in addition, it can calculate change. The placement of も decides what is “also”:

そのアプリはお釣りの計算もできる: among its features, it can also do change calculation.
そのアプリもお釣りの計算ができる: this app, too, can calculate change (others can as well).
そのアプリはお釣りも計算できる: among things it can calculate, it can calculate change too (e.g., tax, tip, and change).

Why is の used between お釣り and 計算?

の links two nouns, making “X’s Y” or “Y of X.” お釣りの計算 literally means “the calculation of change.” You could also express this verbally as お釣りを計算する (“calculate change”).

Is a が missing before できる?

With できる, the thing that is possible is often marked by が (e.g., お釣りの計算ができる). In this sentence, も occupies that slot: お釣りの計算もできる. Using も (or が) is natural; in casual speech, が is often omitted.

Why not use を with できる (e.g., お釣りの計算をできる)?

できる typically takes が for the thing that can be done (or も as in this sentence), not を. Use を with する: お釣りの計算をする. For ability/possibility, prefer 計算ができる.

What’s the difference between できる and できます?

Politeness. できる is plain; できます is polite. Talking to customers or in formal writing, you’d say: そのアプリはお釣りの計算もできます。

What kind of verb is できる?

It’s an ichidan verb meaning “can do/is possible/gets made.” Conjugations: できない (can’t), できた (could/was done), できません (polite negative), できれば (if possible), できそう (seems doable). It functions as the potential of する in meaning, but it’s its own verb.

Does お釣り mean “fishing”? What’s the difference from 釣り?

お釣り (おつり) is “change” (money back). 釣り (つり) by itself commonly means “fishing.” In shops, 釣り can also mean “change,” but お釣り is the standard/polite form. Another word is 釣り銭 (つりせん), more formal/technical.

Can I drop the お and just say 釣り for “change”?

In casual speech some people do, and you’ll hear it in stores. For learners, お釣り is safer and more natural in most contexts.

Why is アプリ in katakana?

It’s a loanword from English (“app/application”). Loanwords are usually written in katakana, hence アプリ.

What’s the difference between その, この, and あの here?

この: “this (near me/the speaker)” → the app I’m holding/using.
その: “that (near you or previously mentioned)” → the app you showed or we just mentioned.
あの: “that (over there/known to both but not near either).” All three are possible depending on context.

Why are there spaces in the sentence? Do Japanese usually write with spaces?

The spaces are for learners. Native writing normally has no spaces: そのアプリはお釣りの計算もできる。

Can I say the same idea with する instead of できる?

Yes, to state the action rather than ability:

Ability: お釣りの計算ができる
Action: お釣りを計算する To keep the “also” nuance with する: そのアプリはお釣りの計算もする (means “it also performs change calculation,” less about capability, more about what it does).

Can も mean “even” here?

Yes, context can make も read as “even.” If change calculation is unexpected, お釣りの計算もできる could be “It can even calculate change.” For stronger emphasis, use さえ: お釣りの計算さえできる.

Is it okay to say そのアプリでお釣りの計算もできる?

Yes. Xで marks the means/tool: “With that app, you can also calculate change.” This frames the app as the tool rather than the topic. Both are natural; choose based on focus.

Can I stack は and も like アプリはも?

No. も replaces the normal particle. Say そのアプリもお釣りの計算ができる (“that app also can…”), not アプリはも.

Would そのアプリがお釣りの計算もできる be okay?

It’s grammatical but unusual. が marks the subject and can sound contrastive/new-information. Describing features is typically topicalized with は: そのアプリは… is more natural.

How do I say it in the negative or past?

Negative: そのアプリはお釣りの計算ができない。/ できません。
Past: そのアプリはお釣りの計算ができた。/ できました。

How do I pronounce the sentence?

Romaji: sono apuri wa otsuri no keisan mo dekiru.
Kana reading: そのアプリはおつりのけいさんもできる.
Natural speech connects smoothly: …りのけ…; all vowels are short.