All articles

The -dik noun clause turns a whole realised statement into a noun, which then serves as the object of a main verb of knowing, saying or thinking.

What this clause does

Turkish has no separate word for the "that" of "I know that he came". To slot a whole statement into a sentence as its object, it turns the statement's verb into a noun with -dik. geldiğini means "that he came", and it stands exactly where a plain object would stand: geldiğini biliyorum, "I know that he came".

Two endings carry the load. A possessive on the -dik form names the subject of the embedded statement, and a case suffix — chosen by the main verb — marks the whole clause as that verb's object. In geldiğini the possessive says "his" and the case closes the clause off, so the single word holds both the subject and its grammatical role.

Four vowel shapes

The suffix comes in four vowel shapes, and four-way vowel harmony picks between them: the vowel inside the suffix matches the stem's last vowel in both dimensions — front or back, rounded or unrounded. A stem whose last vowel is a or ı takes -dık; one in e or i takes -dik; one in o or u takes -duk; one in ö or ü takes -dük.

The two right-hand columns show those four shapes twice: once after a voiced sound, once after a voiceless consonant that turns the opening d into t. The next sections deal with that split, and with a second change that lands once the possessive is added.

Consonant changes at the seam

The suffix opens with a d after a vowel or a voiced consonant, and it hardens to a t after one of the voiceless consonants p ç t k f h s ş. The clause in gittiğini, "that he went", sits on a stem ending in a voiceless sound, so its suffix opens with t; geldiğini, "that he came", sits on a voiced stem and keeps the d.

The bare suffix ends in k — the shapes listed in the table. Add a possessive that opens with a vowel and that k now stands between two vowels, where it softens to ğ. So the shape is -dik, yet the written word is geldiğini, with ğ: the possessive vowel has pulled the softening. This is why the forms you actually write show ğ where the table shows k.

The subject and the closing case

The possessive on the -dik form tells you whose statement it is. A third-person ending marks "he", "she" or "it": geldiğini is "that he came". A first-person ending marks "I": kaldığımı is "that I stayed". A second-person ending marks "you": dediğini is "what you said". When the subject is spelled out it stands in the genitive — benim, senin, onun — and agrees with the possessive, though the pronoun is usually dropped, since the ending already fixes the person.

Onto that possessed form goes a case suffix, and the main verb decides which one. Most verbs that take a fact clause take it as a direct object, so the clause is closed with the accusative: geldiğini biliyorum, "I know that he came". The case is what announces that the whole clause is an argument of the main verb.

Both endings are load-bearing. Drop the possessive and you are left with geldi biliyorum — two finished sentences with nothing joining them. Keep the possessive yet drop the case and geldiği biliyorum leaves the clause floating, unmarked as anyone's object. The reading "I know that he came" needs both, and both together give geldiğini biliyorum.

Five worked clauses

Here are five noun clauses, each waiting for a main verb. Read every one as a nominalised statement — a "that ..." or a "what ..." — ready to slot in front of a verb like bilmek or söylemek.

Two jobs for one suffix

The very same -dik ending builds two different structures. Here it makes a noun: geldiğini takes a case and stands as the object of a verb — geldiğini biliyorum, "I know that he came". In the relative construction it makes a modifier instead: gördüğüm film, "the film I saw", where the -dik form sits in front of a noun, carries no case, and describes it.

The tell is the case. A noun clause is closed off by a case suffix and answers "knows what?" or "said what?". A relative participle carries no case and is followed by the noun it modifies, as in gördüğüm film. Unlike that participle, the noun clause is itself a full argument of the main verb, not a description of some other noun.

Realised facts versus things to come

-dik reports something realised — known, perceived, already the case. geldiğini biliyorum states a fact: he came, and I know it. For a statement about something not yet realised — anticipated, still to happen — Turkish swaps the nominaliser to -acak. geleceğini is "that he will come", the prospective counterpart of the factual geldiğini.

Both slot into the same frame: a possessive for the subject, a case for the role. They differ only in the nominaliser — -dik for the realised, -acak for the prospective. Picking between them is picking whether the embedded statement is already a fact or still to come.

Verbs that take a fact clause

A definable set of main verbs takes a whole noun clause as its object — verbs of knowing, thinking, saying and perceiving. bilmek "to know", düşünmek "to think", söylemek "to say" and anlamak "to understand" each govern a -dik clause: haklı olduğunu düşünüyorum is "I think that he is right", and Türkçe bildiğini söyledi is "he said that he knows Turkish".

The case comes from the main verb

Which case closes the clause is the main verb's business, exactly as it would be for a plain noun object. Most fact verbs take the accusative, so the clause ends in it: geç kaldığımı fark ettim, "I realised that I was late". A verb that governs the dative pulls the clause into the dative instead: sevinmek, "to be glad", gives geldiğine sevindim, "I was glad that he came", with geldiğine in the dative where kaldığımı stands in the accusative.

Reporting an embedded question

The same clause carries an indirect question — "what", "where", "who". The question word stays inside the clause and the verb still nominalises with -dik: ne dediğini anlamadım, "I didn't understand what you said", and nereye gittiğini bilmiyorum, "I don't know where he went". kim olduğunu bilmiyorum is "I don't know who he is".

A hidden consonant before the case

One consonant appears that no suffix put there. After a third-person possessive — a bare vowel — a buffer -n- slides in ahead of the case suffix so the two vowels never meet. That is why the accusative on geldiğini surfaces as a syllable with n, and the dative on geldiğine does too: the -n- glues the possessive vowel to the case ending.

This buffer belongs to the third-person possessive alone. After a first- or second-person possessive, which already ends in a consonant, the case attaches straight on with no glide: the accusative in kaldığımı and in dediğini follows the possessive directly, with no -n- in sight.