Bugün senin yorgun olduğunu biliyorum.

Breakdown of Bugün senin yorgun olduğunu biliyorum.

olmak
to be
bugün
today
bilmek
to know
senin
your
yorgun
tired
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Questions & Answers about Bugün senin yorgun olduğunu biliyorum.

Can you break down the sentence grammatically, word by word?
  • Bugün – “today”; an adverb of time.
  • senin – “your / of you”; the pronoun sen (“you”) in the genitive case.
  • yorgun olduğunu – literally “your being tired / the fact that you are tired”; this whole chunk is the object of the verb bilmek.
  • biliyorum – “I know”; from bil- (to know) + -iyor (present/progressive) + -um (1st person singular).

So syntactically, “senin yorgun olduğunu” is a noun‑like clause (“the fact that you are tired”) and biliyorum is the main verb, “I know (it) today.”

Why is it senin and not just sen?

In Turkish, when you turn a clause into a noun with -DIK (like olduğunu, geldiğini, etc.) and use it as an object or subject, the subject of that clause appears in the genitive case.

The pattern is:

[GENITIVE subject] + [verb + -DIK + possessive]

Examples:

  • Ali’nin geldiğini biliyorum. – “I know that Ali came / is coming.”
  • Onun hasta olduğunu duydum. – “I heard that he/she is sick.”

So here:

  • senin = “of you / your” → genitive subject of the embedded clause.
  • (senin) yorgun olduğunu = “your being tired”.

Using sen instead of senin in this structure (Sen yorgun olduğunu biliyorum) is ungrammatical. However, you can simply omit the pronoun altogether if it’s clear from context:

  • Bugün yorgun olduğunu biliyorum. – “I know (that) you are tired today.” (to the person you’re talking to)
What exactly does yorgun olduğunu mean, and how is it built?

yorgun olduğunu corresponds to English “that you are tired”, but literally it is something like “your being tired”.

Breakdown:

  • yorgun – adjective: “tired”.
  • ol‑duğ‑un‑u:
    • ol‑ – verb root: “to be / to become”.
    • ‑duğ‑ – a form of the nominalizing suffix ‑DIK (changes shape: ‑dık / ‑dik / ‑duk / ‑dük / ‑duğ / ‑düğ, etc. by vowel harmony and consonant rules).
    • ‑un2nd person singular possessive (“your”).
    • ‑uaccusative case marker (“the fact that …” as a direct object).

So:

yorgun ol‑duğ‑un‑u
tired be‑DIK‑2SG.POSS‑ACC
= “your being tired / the fact that you are tired”.

Combined with biliyorum:

  • Bugün senin yorgun olduğunu biliyorum.
    ≈ “Today, I know your being tired.” → “I know that you are tired today.”
If olduğunu looks like the past tense (oldu = “became/was”), why does the sentence mean “you are tired”, not “you were tired”?

It’s tempting to see olduğunu as oldu (past) + something, but in this construction the crucial piece is ‑DIK (here surfacing as ‑duğ‑), which is a nominalizing suffix, not an independent past tense.

So in olduğunu:

  • The ‑duğ‑ part is from ‑DIK, which turns the verb into a nounlike form (“the fact that X is/was…”, “the act of X doing…”).
  • It does not itself fix the time (present vs past); the time is usually read from:
    • context words like bugün (“today”, present) or dün (“yesterday”, past),
    • and/or the tense of the main verb (biliyorum, biliyordum, etc.).

So:

  • Bugün senin yorgun olduğunu biliyorum.
    → By bugün, we understand: “I know that you are tired today.”
  • Dün senin yorgun olduğunu biliyordum.
    → With dün and past on bilmek: “I knew that you were tired yesterday.”

The ‑DIK form here is about turning the clause into a thing (“the fact that you are/were tired”), not about marking past tense.

Why is there an extra ‑u at the end of olduğunu? Could we say Bugün senin yorgun olduğun biliyorum?

No, “Bugün senin yorgun olduğun biliyorum” is not correct in standard Turkish.

The last ‑u in olduğun‑u is the accusative case marker. The whole phrase senin yorgun olduğunu is the direct object of biliyorum (“I know what? → your being tired”), and in Turkish, a definite/specific direct object normally takes the accusative.

Structure:

  • ol‑duğ‑un‑u
    • ‑un – “your” (2nd sg possessive; attaches because senin is the subject of the embedded clause),
    • ‑u – accusative (marks the whole embedded clause as the object of bilmek).

Compare:

  • Senin geldiğini biliyorum.
    gel‑diğ‑in‑i → “I know that you came / are coming.”
  • Senin geldiğin biliyorum. – ungrammatical in this sense.

So you should keep the final ‑u:

  • Bugün senin yorgun olduğunu biliyorum.
  • Bugün senin yorgun olduğun biliyorum.
What exactly is the role of senin yorgun olduğunu in the sentence? Is it really like saying “your being tired”?

Yes. In terms of grammar function, senin yorgun olduğunu acts as a noun phrase (a single “thing”), and that “thing” is the object of the verb bilmek.

You can think of the structure as:

[GENITIVE subject] + [VERB + -DIK + possessive]
= “the fact that [subject] [verb]” / “[subject]’s [verb]‑ing”

Examples with the same pattern:

  • Ali’nin geldiğini biliyorum.
    “I know that Ali came / will come / has come (depending on context).”
  • Onun hasta olduğunu duydum.
    “I heard that he/she is sick.”
  • Senin sınavı geçeceğini düşünüyorum.
    “I think that you will pass the exam.”

So:

  • senin – GENITIVE subject: “your”
  • yorgun olduğunu – “being tired” (a nominalized verb phrase)
  • Together: “your being tired / the fact that you are tired”

This entire chunk is what you know.

Can we leave out senin? What changes if we just say Bugün yorgun olduğunu biliyorum?

Yes, you can leave it out; Turkish often drops pronouns when the subject is clear from context.

  • Bugün senin yorgun olduğunu biliyorum.
    Explicitly: “I know that you are tired today.”
  • Bugün yorgun olduğunu biliyorum.
    Literally: “I know that (someone) is tired today.”

Without senin, the embedded subject is not overtly stated, and grammatically the default reading is 3rd person (“he/she/they are tired”). However, in actual conversation, if you say this to someone directly, it will usually be understood as “I know that you are tired today” from context.

You add senin mainly when you:

  • want to make the subject crystal clear,
  • or contrast it with someone else (e.g., “I know you are tired, not him.”).
Can we change the word order, for example Senin bugün yorgun olduğunu biliyorum? Does the meaning change?

You have quite a bit of word‑order freedom in Turkish, mainly for emphasis, not for basic meaning.

All of these are grammatically fine:

  • Bugün senin yorgun olduğunu biliyorum.
  • Senin bugün yorgun olduğunu biliyorum.
  • Senin yorgun olduğunu bugün biliyorum. (less common, emphasizes today in relation to the knowing)

The core structure senin yorgun olduğunu biliyorum stays the same. Moving bugün changes what is slightly emphasized:

  • Bugün senin yorgun olduğunu biliyorum.
    Often read as “As for today, I know you’re tired.”
  • Senin bugün yorgun olduğunu biliyorum.
    Feels a bit more like “I know that you are tired today (as opposed to some other time or other person).”

What you cannot do is break up the internal chunks in an unnatural way, such as:

  • Bugün senin yorgun biliyorum olduğunu.

The pieces yorgun olduğunu belong together as a unit.

Is there a more direct way to say this in Turkish, without the -DIK structure?

Yes. You can express essentially the same idea with two separate clauses:

  • Bugün yorgunsun, biliyorum.
    “You’re tired today, I know.”
  • Bugün yorgunsun; bunu biliyorum.
    “You’re tired today; I know this.”

Differences:

  • Bugün senin yorgun olduğunu biliyorum.
    Uses a single sentence with an embedded clause as the object of biliyorum; a bit more compact / formal.
  • Bugün yorgunsun, biliyorum.
    Feels more like a statement plus a comment about it; very natural in spoken language.

Both are correct; the original simply shows you how Turkish commonly builds “I know that …” with an object clause.

How would we say variants like “I know that you are not tired today” or “I knew that you were tired”?
  1. Negative (“I know that you are not tired today”)

    • Bugün senin yorgun olmadığını biliyorum.

    Breakdown of olmadığını:

    • ol‑ – “to be / become”
    • ‑ma‑ – negative
    • ‑dığ‑ – nominalizer (‑DIK)
    • ‑ın – 2nd person singular possessive
    • ‑ı – accusative

    So: “I know the fact that you are not tired today.”

  2. Past knowing (“I knew that you were tired”)

    • Bugün senin yorgun olduğunu biliyordum.
      “I knew (at that time) that you were tired today.”
      (Commonly you’d say Dün instead of Bugün for a more natural context:)

    • Dün senin yorgun olduğunu biliyordum.
      “I knew yesterday that you were tired.”

    Here:

    • The embedded clause still uses olduğunu (same ‑DIK nominalization),
    • The main verb changes from biliyorum (“I know”) to biliyordum (“I knew”).

So you keep the same senin … olduğunu / olmadığını pattern inside the clause, and you adjust time mainly through adverbs (bugün, dün) and the tense of biliyorum / biliyordum.