Learn Hardcore Turkish: Her zamanki kahveyi içmektense bitki çayı denemek ister misin? - Would you rather try herbal tea than drink the usual coffee?

It’s the converb -(m)AktAnsA, historically -mek + den/ten + ise → -mektense, meaning rather than doing X. You attach it to a verb’s infinitive to compare two actions: rather than V1, (do) V2. Here: rather than drinking, try …

Ablative alternates by consonant/vowel harmony: -dan/-den/-tan/-ten.
The final -se is from ise, reduced to -se/-sa by harmony.
Spelling is one word: e.g., içmektense, yemektense.

Why is kahveyi in the accusative (-i)?

Because it’s a specific object inside the verbal noun phrase kahveyi içmek. In Turkish, when an object is specific/definite, it takes accusative even with an infinitive:

Non-specific: kahve içmek (to drink coffee, in general)
Specific: her zamanki kahveyi içmek (to drink the usual coffee)

The buffer consonant -y- appears because kahve ends in a vowel: kahve + i → kahveyi.

Why isn’t bitki çayı in the accusative here?

It’s an indefinite/new object of denemek (to try), so it stays bare: bitki çayı denemek. If you meant a specific, previously-mentioned herbal tea, you’d use accusative: bitki çayını denemek.

Do both verbs have to be in the infinitive around -mektense?

The first action must be in the infinitive for -mektense. The second action can be:

Another infinitive governed by a verb like istemek/tercih etmek: … bitki çayı denemek ister misin?
A finite verb: … bitki çayı dener misin? Both are acceptable; the sentence you saw uses the polite invitation pattern with istemek.

What’s the nuance difference between denemek ister misin? and dener misin?

denemek ister misin? literally would you like to try? It’s softer/politer and very common for offers.
dener misin? would you try? Also polite, but can feel a bit more direct or request-like.
istiyor musun? (Do you want?) is more direct/neutral.

What does her zamanki mean morphologically, and how does -ki work here?

her every
zaman time
-ki turns the time expression into a determiner meaning the one of that time → the usual. So her zamanki kahve ≈ the usual coffee. The suffix -ki creates adjectival/pronominal forms from nouns/adverbs (e.g., dünkü, evdeki).

Could I replace the noun with a pronoun like “the usual one”?

Yes: Her zamankini içmektense … Here, her zamanki + (n)i becomes a pronoun (the usual one) in accusative. This avoids repeating kahve.

Why is bitki çayı formed that way? Is there a special compound rule?

Yes, it’s an indefinite noun compound:

bitki (plant) + çay (tea) + 3sg possessive on the head → bitki çayı (herbal tea). In such compounds, the second noun carries -(s)I: çayı.

Could I say Her zamanki kahve yerine instead of using -mektense?

Yes:

Her zamanki kahve yerine bitki çayı denemek ister misin?
Or with a verb noun: Her zamanki kahveyi içmek yerine … Nuance: -mektense often has a slight preference/contrastive feel (rather than …), while -yerine is a bit more neutral (instead of …). Both are natural here.

Why is it içmektense and not içmekdense?

Because of the ablative allomorph: after a voiceless consonant like k, the ablative is -ten (not -den). So:

içmek + ten + ise → içmektense After voiced sounds/vowels you’d see -dan/-den, e.g., yemektense, oynamaktansa.

Is a comma needed before içmektense or after that clause?

Not strictly required, but a comma can improve readability when the “rather than …” part comes first:

Her zamanki kahveyi içmektense, bitki çayı denemek ister misin?

How flexible is the word order?

Turkish word order is flexible. Common variants:

Her zamanki kahveyi içmektense, bitki çayı denemek ister misin? (as given; very natural)
Bitki çayı denemek ister misin, her zamanki kahveyi içmektense? (possible, slightly more conversational) Keep the -mektense clause intact, and place the question particle mi-word near the end.

Why is the question particle in ister misin separate, and why misin specifically?

The clitic mi/mı/mu/mü is written separately and follows vowel harmony. It also carries personal endings:

Base: mi
Vowel harmony: mi/mı/mu/mü
With 2sg: misin/mısın/musun/müsün Here, harmony with ister yields misin: ister misin?

Could I just say Bitki çayı dener misin? and drop the “rather than …” part?

Yes, that’s a simple, polite request to try herbal tea. The original sentence adds the contrast with the usual coffee, which frames it as an alternative.

Is there any difference between içmektense and expressions like içmekten ziyade?

They’re close. -mekten ziyade (rather than, more than) is a bit more formal or literary. -mektense is compact and very common in speech. Both work here with only subtle stylistic differences.

Does the aorist in ister have a special nuance?

Yes. The aorist (habitual) form of istemek—ister—is standard in offers and polite invitations: İster misin? is the default polite way to ask Would you like …?, more courteous than the progressive istiyor musun?.