Learn Hardcore Turkish: Mert tutumlu davranıyor, Ayşe ise harcamalarını dikkatle izliyor. - Mert acts frugally, while Ayşe carefully tracks her spending.

It’s a contrastive topic marker meaning “as for” or “whereas.” So Ayşe ise ≈ “as for Ayşe/whereas Ayşe,” contrasting her with Mert. It’s not the verb “is.”

Can I replace "ise" with "ama" (but) or "ve" (and)? What changes?

ama makes the contrast explicitly adversative: “..., but Ayşe ...”
ve is additive: “..., and Ayşe ...”
ise contrasts two topics more neutrally, often like “whereas/as for.”
All three are grammatical but carry different discourse vibes.

Is the comma before “Ayşe ise” necessary?

It’s standard to separate the two clauses with a comma or a semicolon:

Mert tutumlu davranıyor; Ayşe ise... (a bit more formal)
Mert tutumlu davranıyor, Ayşe ise... (very common) Leaving no punctuation there is unusual.

Why is “harcamalarını” in the accusative?

Because it’s a definite direct object (“her expenses”). In Turkish, definite objects take the accusative. Morphology:

harcama-lar-ı-nı
- harcama = expense/spending
- -lar = plural
- -ı = 3rd person possessive (her/his)
- -n- = buffer consonant
- -ı = accusative case

Does “harcamalarını” necessarily mean her own expenses? Should I add “kendi”?

By default it will be understood as “her (Ayşe’s) expenses,” especially since Ayşe is the subject. If you want to emphasize it’s specifically her own (and not, say, her family’s or someone else’s), you can say kendi harcamalarını.

Why plural “harcamalarını” and not singular “harcamasını”?

harcamalarını (plural) suggests tracking multiple transactions/expense items.
harcamasını (singular) focuses on spending as a single overall category.
Both are possible; plural is more natural when you imagine itemized expenses.

Could I say “harcamalar” without accusative?

That would change the meaning. Harcamalar (no possessive, no accusative) means “expenses” in general and can be read as a subject or an indefinite object. Here we want “her expenses” as a definite object, so harcamalarını is the right form.

Why is it “izliyor” and not “izleyor”?

The present continuous is -(I)yor. With vowel-final stems, Turkish never uses “-eyor/-ayor.” Instead, you get one of -ıyor/-iyor/-uyor/-üyor by vowel harmony:

izle-
- -(I)yor → izliyor
Compare: bekliyor, söylüyor, anlıyor, okuyor
So “izleyor” is not a valid form.

What’s the nuance of “davranıyor” vs “davranır”?

davranıyor (present continuous) = “is behaving (these days/right now),” often temporary or current tendency.
davranır (aorist) = habitual/generic: “behaves (is the kind of person who behaves) frugally.”
Your sentence paints a current or ongoing picture.

Why say “tutumlu davranıyor” instead of just “tutumlu”?

Mert tutumlu = “Mert is thrifty” as a character trait.
Mert tutumlu davranıyor = “Mert is acting/behaving thriftily (now/these days),” focusing on behavior rather than inherent trait.

Is “dikkatle” the only correct choice? What about “dikkatlice” or “dikkatli”?

All three occur:

dikkatle = “with care,” slightly formal/neutral.
dikkatlice = adverb “carefully,” common in everyday use.
dikkatli (adj) is often used adverbially in speech: dikkatli izliyor is natural.
You could also use özenle (“meticulously”).

Where can I put “dikkatle” in the sentence?

Turkish word order is flexible before the verb. All are acceptable, with subtle focus differences:

Ayşe ise harcamalarını dikkatle izliyor. (neutral, manner right before verb)
Ayşe ise dikkatle harcamalarını izliyor. (slightly more emphasis on “carefully”)
Ayşe ise harcamalarını izliyor dikkatle. (colloquial, afterthought emphasis)

Can I use “takip etmek,” “kontrol etmek,” or “denetlemek” instead of “izlemek”?

Yes, with nuances:

izlemek = monitor/track over time (very natural here).
takip etmek = follow/track (also common for expenses).
kontrol etmek = check/control (periodic checking rather than continuous monitoring).
denetlemek = audit/supervise (more formal/official).

What’s the difference between “Ayşe ise” and “Ayşe’yse”?

They’re equivalent in meaning. Ayşe ise writes the contrastive particle as a separate word. Ayşe’yse attaches the clitic form -yse to the proper name (with an apostrophe, as is standard for suffixes on proper nouns). Both are widely used.

How is “ise” different from “de/da” (“too/also”)?

Ayşe de harcamalarını dikkatle izliyor. = “Ayşe also carefully tracks her expenses” (additive).
Ayşe ise... = “As for Ayşe/whereas Ayşe...” (contrastive topic).
Choose based on whether you want addition or contrast.

Are there synonyms for “tutumlu (davranmak)”?

Yes:

idareli (davranmak) = frugal/using resources sparingly.
ekonomik can mean economical/efficient, but for people it’s less idiomatic; prefer tutumlu/idareli for “frugal.”
Avoid using ucuz for people; it means “cheap” (things), not “frugal.”