Learn Hardcore Turkish: Lütfen termosu getir, çaydanlıktaki çayı içine dökelim. - Please bring the thermos, let’s pour the tea from the teapot into it.

Lütfen: please (politeness marker)
termosu: termos + -u (accusative “the thermos,” definite object; vowel harmony -> -u after o)
getir: bring (2nd person singular imperative)
çaydanlıktaki: çaydanlık + -ta (locative “in the teapot/kettle”) + -ki (relativizer “the one that is in …”)
çayı: çay + -ı (accusative “the tea,” definite object)
içine: iç (“inside”) + -i (3rd person possessive “its inside”) + -e (dative “into”) with buffer -n- after a possessive: içi + -e → içine
dökelim: dök- (pour) + -elim (hortative/optative “let’s …”; vowel harmony with ö → -elim)

Why are termosu and çayı in the accusative?

Turkish marks definite direct objects with the accusative. Here we mean a specific thermos and the specific tea in the teapot, so:

termosu getir = bring the thermos (that specific one)
termos getir = bring a thermos (any thermos) Similarly:
çayı dökelim = let’s pour the tea (specific)
çay dökelim = let’s pour (some) tea (indefinite)

What does the -ki in çaydanlıktaki do? Why not just çaydanlıkta?

çaydanlıkta means “in the teapot/kettle,” describing location.
çaydanlıktaki turns that location phrase into an adjective: “the one that is in the teapot.” So çaydanlıktaki çay = “the tea that is in the teapot.” This is the standard way to say “the X that is in/on Y.”

What exactly is içine referring to, and why does it have a possessive ending?

İçine literally means “into its inside.” The 3rd person possessive -i points back to something already mentioned—in this case, the thermos. So içine dökelim = “let’s pour (it) into it.” You could also say:

termosun içine (explicit: “into the thermos’s inside”)
or simply termosa (“into the thermos,” using dative), which is also common.

Could I replace içine with termosa?

Yes. Çaydanlıktaki çayı termosa dökelim is natural and common. Using içine is a bit more explicit about “inside,” while termosa relies on context (with containers, dative typically implies “into”).

Why mix getir (imperative) with dökelim (“let’s” form)?

This is very natural: you directly ask the listener to bring the thermos (getir), then propose a joint action (dökelim). It implies: “You bring it, then we (together) pour.” If you wanted both to be joint suggestions, you’d say getirelim … dökelim, but that means “let’s bring … and let’s pour,” not “please bring …”

Is there a more polite way to say “bring” here?

Yes. Commonly:

Lütfen termosu getirir misin? (Could you bring the thermos, please? singular)
Lütfen termosu getirir misiniz? (polite/plural) The rest can stay the same: …, çaydanlıktaki çayı içine dökelim.

Why is there a comma instead of ve (“and”)?

Turkish often uses a comma to sequence short clauses, especially with imperatives/suggestions. Ve would also work: Lütfen termosu getir ve çaydanlıktaki çayı içine dökelim, but the comma is natural and slightly snappier.

How does dökelim work? Is it a command?

It’s the hortative/optative first-person plural: “let’s pour.” Form: verb stem + -alım/-elim per vowel harmony. It’s a suggestion/invitation, not a command. If you wanted to command the listener, you’d use dök (2sg imperative) or dökün (2pl).

Could I say dökelim mi? What’s the difference?

dökelim = a confident proposal (“let’s pour”).
dökelim mi? = a question (“shall we pour?”), seeking confirmation/consent.

Is the word order fixed? Can I move things around?

You have flexibility. Some natural variants:

Lütfen termosu getir, çaydanlıktaki çayı termosa dökelim.
Lütfen çaydanlıktaki çayı termosun içine dökelim. (one clause)
Çaydanlıktaki çayı termosun içine dökelim, lütfen. (moving lütfen; more formal/emphatic) Within the clause, both Çayı termosa dökelim and Termosa çayı dökelim are possible; default is usually object before the verb, and destination often comes right before the verb too. Word order choices affect emphasis more than grammaticality.

What’s the nuance of dökmek vs alternatives like koymak, boşaltmak, akıtmak?

dökmek: to pour (general, especially for liquids).
koymak: to put/place (not used for pouring liquids into a container).
boşaltmak: to empty out/pour out (emphasis on emptying a container).
akıtmak: to let flow/drain (more about flowing).

Here, dökelim is the most natural.

Do I need to say biz or sen for the subjects?

No. Turkish verb forms mark person:

getir → “(you) bring” (2nd singular imperative; “sen” is understood).
dökelim → “let’s (we) pour” (1st plural hortative; “biz” is understood).

What if I’m addressing more than one person?

Use the plural imperative for the first clause:

Lütfen termosu getirin, çaydanlıktaki çayı içine dökelim. The second clause stays dökelim if you still mean “let’s (all) pour.”

Why is it çaydanlıktaki with -ta-, not -da-?

The locative suffix is -da/-de/-ta/-te, chosen by consonant voicing and vowel harmony. Since çaydanlık ends with the voiceless consonant k, you take the voiceless variant -ta → çaydanlıkta, then add -ki → çaydanlıktaki.

How does vowel harmony show up in the suffixes here?

termosu: accusative -u (back, rounded) after the back rounded vowel o.
çayı: accusative -ı (back, unrounded) after a.
dökelim: hortative -elim (front) after front vowel ö.
-ta in çaydanlıkta: voiceless variant with back vowel.

Could I say çaydanlıktaki çay without the accusative?

Not in this sentence. As the definite direct object of a transitive verb (dökmek), it needs the accusative: çaydanlıktaki çayı. Without accusative, it would read as an indefinite/”some tea” and sounds off here (and would usually require a different construction, e.g., using the ablative for “from”: Çaydanlıktan çay dökelim = “Let’s pour some tea from the teapot”).

Is içerisine okay instead of içine?

Yes. içerisine is a longer, slightly more formal/specific variant of içine. Both are correct: … çayı içerisine dökelim.

What’s the difference between çaydanlık and demlik?

çaydanlık: the kettle set used for Turkish tea (often the larger lower pot, but can refer to the whole set).
demlik: the (smaller) teapot on top where the tea concentrate is brewed. In daily speech, çaydanlık can loosely refer to the part holding the tea; context clarifies.

Could I also use onun içine for clarity?

Yes: … çayı onun içine dökelim (“… let’s pour the tea into it”). It explicitly says “into its inside,” where onun refers back to the thermos. Usually içine alone is clear enough when the referent was just mentioned.