Yanımızda su olsun diye termosları doldurduk.

We filled the thermoses so we would have water with us.

Breakdown of Yanımızda su olsun diye termosları doldurduk.

• olmak: to be
• su: the water
• diye: so that
• doldurmak: to fill
• termos: the thermos
• yanımızda: with us

Questions & Answers about Yanımızda su olsun diye termosları doldurduk.

What exactly does yanımızda mean, and how is it formed?

It literally means “at our side,” and in context it conveys “with us / on us (in our possession).” Morphology:

• yan = side
• -ımız = our (1st person plural possessive)
• -da = at/in/on (locative) So yan-ımız-da = “at our side,” often used for things you have on you or are carrying.

Why use yanımızda instead of bizimle?

• bizimle = “with us” in the sense of accompanying people (e.g., “Come with us” = Bizimle gel).
• yanımızda = “with us/on us” in the sense of being physically by us or in our possession (e.g., money, water, keys). Here we mean “to have water on us,” so yanımızda is the natural choice.

What does olsun diye mean here?

It expresses purpose: “so that there (will) be,” “in order that there be.”

• ol-sun = “may it be / let it be” (optative mood, 3rd singular of ol- “to be”)
• diye = a conjunction/postposition meaning “so that / with the intention that” Together, … olsun diye … = “(we did X) so that (Y) would be.”

Why use olsun and not something like var olsun or bulunsun?

• olsun with su is idiomatic: su olsun ≈ “let there be water / have water.”
• bulunsun is possible and a bit more formal or written, emphasizing “be present/available.”
• var olsun is not used in this sense; var is a predicate (“there is”), and combining it with olsun sounds off here.

Can I use için instead of diye?

Yes, with a small structural change:

• Yanımızda su olması için termosları doldurduk. Here için takes a nominalized clause (su olması “there being water”).
  Nuance: … diye is very common and conversational for purpose; … için is neutral/slightly more formal. Both are correct.

What case is termosları, and why is it marked?

It’s accusative plural, marking a definite direct object: termoslar-ı = “the thermoses.”
In Turkish, definite direct objects take accusative. If you meant “we filled thermoses (some, not specific ones),” you’d typically say termoslar doldurduk (no accusative), though with “fill,” a definite set is more natural.

Could termosları also mean “their thermoses”?

Yes, termosları can be ambiguous between:

• accusative plural: “the thermoses”
• 3rd person plural possessive: “their thermoses” Context disambiguates. If you needed to be explicit:
• “their thermoses” (definite object): onların termoslarını
• “our thermoses”: termoslarımızı

What is the breakdown of doldurduk?

• dol- = to be full
• -dur- = causative (make something full) → doldur- = to fill
• -du- = simple past (due to vowel harmony, it’s -du/-dı/-dü/-dü or -tu/-tı/-tü/-tü)
• -k = 1st person plural “we” So doldurduk = “we filled.”

Why is the past suffix here -du- and not -dı or -tü?

Vowel harmony and consonant voicing rules:

• The last vowel in doldur- is u, so the past vowel harmonizes to u → -du.
• The stem ends in a voiced consonant (r), so the suffix starts with d (not t). Hence doldur-duk.

What is the subject of su olsun? Why no word meaning “there”?

The subject is su (“water”). Turkish doesn’t use an explicit dummy “there” like English. su olsun literally “water may-be” = “let there be water.”

Can the word order change?

Yes. Turkish word order is flexible, especially for adverbial purpose clauses. Common options:

• Yanımızda su olsun diye termosları doldurduk. (purpose first)
• Termosları yanımızda su olsun diye doldurduk. (object first)
• Termosları doldurduk, yanımızda su olsun diye. (purpose after the verb, often with a pause/comma) All are natural.

How would I say it with a single thermos or specify the filling substance?

• Single thermos: Termosu doldurduk.
• Specify with water: Termosları suyla (su ile) doldurduk.
  In your sentence, su is already mentioned in the purpose clause, so it’s understood; adding suyla is optional emphasis.

Could I say something like “so that we could take water with us” instead?

Yes, using almak (“to take”):

• Yanımıza su almak için termosları doldurduk. Here yanımıza (to our side) + su almak (to take water) frames the purpose as the action of taking water along, rather than the state of “there being water with us.” Both are fine; your original emphasizes the end state.

How would I make the purpose clause negative?

Use the negative of olsun: olmasın.

• (… ) yanımızda su olmasın diye … = “so that there wouldn’t be water with us.”
  It’s grammatically fine, though the overall meaning must make sense in context (e.g., you wouldn’t fill thermoses to avoid having water). You can also negate with olmaması için using için:
• Yanımızda su olmaması için …