Learn Hardcore Turkish: Sen hafta sonuna kadar projeyi tamamlamış olacaksın. - You will have completed the project by the weekend.

It’s the Turkish future perfect: perfect marker -mış on the main verb + auxiliary ol- in the future (-acak) + person (-sın). It means “you will have completed,” i.e., the state of being finished will hold by a future reference time.

Why use tamamlamış olacaksın instead of the simple future tamamlayacaksın?

tamamlayacaksın: “you will complete (at some point in the future).”
tamamlamış olacaksın: “by that time, you will already be in the state of having completed.” It highlights completion before or by a deadline (here, the weekend) and often sounds like an expectation or prediction.

Can you break down the morphology of tamamlamış olacaksın?

tamamla-: verb stem “to complete”
-mış: perfect/resultative marker (also the “evidential” past in other uses)
ol-: auxiliary “to be”
-acak: future
-sın: 2nd person singular Whole: “you will be (in the state of) having completed.”

Is the subject pronoun Sen necessary?

No. Sen is optional because -sın already marks 2nd person. Using Sen adds emphasis or contrast (e.g., “YOU will have finished …”).

What does the -yi in projeyi do? Why not just proje?

-i is the accusative for a definite direct object (“the project”). Because proje ends in a vowel, a buffer -y- appears: proje + yi → projeyi. Without -i, the object is indefinite (“a project”), which would be either bare (proje) or with bir proje.

Why is it hafta sonu-na (with -n-) and not hafta sonu-ya? Where does that n come from?

hafta sonu is an (indefinite) noun compound whose second noun carries an implicit 3rd-person possessive (son-u). When you add a case suffix to such a possessed form, Turkish inserts a buffer -n-: sonu + a → sonuna. Then you add the postposition kadar.

Does … kadar mean “by” or “until”?

Both, depending on aspect:

With perfect/future perfect (as here): “by” a time limit (completion before that point).
With ongoing actions: “until” (duration up to that point). So here, hafta sonuna kadar = “by the weekend.”

Can I say hafta sonundan önce instead of hafta sonuna kadar?

Yes. …dan önce (ablative + önce) also means “before/by.” Nuance:

…a kadar emphasizes the boundary you reach by that time.
…dan önce emphasizes “at some time prior to” that point. In most deadline contexts, both are fine.

Where does the yes/no question particle go? How do I ask “Will you have finished by the weekend?”

Place the clitic after the finite verb (here, olacak), and it carries person:

Hafta sonuna kadar projeyi tamamlamış olacak mısın? Note vowel harmony: mı/mi/mu/mü matches the preceding vowel (here, a → mı), and the person suffix attaches to it: mı-sın → mısın.

How do I negate it: “You will not have completed the project by the weekend”?

Negate the auxiliary: Hafta sonuna kadar projeyi tamamlamış olmayacaksın. Don’t use değil with verbs here; use ol- in the negative future (olmayacak-).

Can I use bitirmek instead of tamamlamak?

Yes:

Bitirmiş olacaksın ≈ “you will have finished.”
Tamamlamış olacaksın ≈ “you will have completed.” They’re often interchangeable; tamamlamak can sound a touch more formal/“complete in all parts.”

Can I move elements around? Does word order change emphasis?

Yes. The element immediately before the verb complex is typically in focus.

Neutral-ish: Sen hafta sonuna kadar projeyi tamamlamış olacaksın. (object near focus)
Deadline focus: Sen projeyi hafta sonuna kadar tamamlamış olacaksın.
Object focus: Hafta sonuna kadar projeyi tamamlamış olacaksın. All are grammatical; choose order to highlight what matters.

Why is it -mış (not -miş) and -acak (not -ecek)? Vowel harmony?

Right. Turkish suffix vowels harmonize with the last vowel of the stem:

tamamla- has a back vowel (a) → back unrounded variant -mış.
ol- has a back vowel (o) → -acak, and 2sg -sın (back ı).

Can this construction express an assumption, like English “You’ll have finished by now”?

Yes. With adverbs like şimdiye kadar, -mış ol- + future can convey a reasoned guess:

Şimdiye kadar projeyi tamamlamış olacaksın. = “You’ll have finished by now (I assume).” For a stronger “must have,” you can also use …miş olmalısın or …mişsindir.

What’s the passive/subjectless alternative if I don’t want to say “you”?

Use the passive of the project:

Hafta sonuna kadar proje tamamlanmış olacak. This says “The project will be (have been) completed by the weekend.”

How do I give a deadline command like “Have the project completed by the weekend”?

Use the perfect + ol imperative:

Hafta sonuna kadar projeyi tamamlamış ol! This is a common way to set deadlines/instructions.

Do I need a postposition to say “by the weekend,” or can I just use the dative?

You need a postposition. Dative alone (hafta sonuna) means “to the weekend.” For “by/until,” use …a kadar/dek, or use …dan önce for “before.”

What if I mean “a project,” not “the project”?

Make the object indefinite:

Hafta sonuna kadar bir proje tamamlamış olacaksın. (“You will have completed a project.”) Avoid accusative -i on proje unless it’s specific/definite.