Learn Hardcore Turkish: Bavulumu hazırlamadan tatile gidebileceğimi sanmıyorum. - I don’t think I can go on vacation without packing my suitcase.

bavul – suitcase
-um – my (1st person singular possessive) → bavulum = my suitcase
-u – accusative case ending (direct object marker) → bavulumu = my suitcase as a specific object

So bavulumu literally means “my suitcase” as a specific direct object of hazırlamak (to pack/prepare).

In Turkish, when you have a specific thing being acted on, you usually mark it with the accusative:

Bavulumu hazırlıyorum. – I am packing my suitcase.
Bavul hazırlıyorum. – I am packing (a) suitcase / I am packing suitcases (non-specific).

That’s why it’s bavulumu, not just bavulum or plain bavul.

What does hazırlamadan mean, and why not just use hazırlamak?

Hazırlamadan comes from the verb hazırlamak (to prepare/pack) and means “without preparing/without packing”.

Formation:

hazırlamak → remove -mak → hazırlama-
add the converb suffix -dan / -den / -tan / -ten → hazırlamadan

The suffix -madan / -meden means:

“without doing X” (most common translation)
sometimes also “before doing X”, depending on context

So:

Bavulumu hazırlamadan tatile gidebileceğimi sanmıyorum.
≈ I don’t think I can go on vacation *without packing my suitcase.*

If you used hazırlamak instead, the sentence would be ungrammatical here, because you need a “without doing” form, not just the infinitive.

Is -madan always “without doing”, and how is it generally formed?

Yes, -madan / -meden usually means “without doing (verb)” and is a very common structure.

General formation:

Take the infinitive -mak / -mek form:
- gitmek (to go), yemek (to eat), okumak (to read)
Drop -mak / -mek:
- git-, ye-, oku-
Add -meden / -madan with vowel harmony:
- gitmeden – without going
- yemeden – without eating
- okumadan – without reading

Examples:

Konuşmadan gitme. – Don’t leave without speaking.
Sabah kahvaltı yapmadan okula gittim. – I went to school without having breakfast.

In your sentence, hazırlamadan = without preparing/packing.

Why is it tatile and not something like tatil or tatilde?

The root is:

tatil – vacation / holiday

Then we add -e / -a (dative case) → tatile, which literally means “to vacation” or “to the holiday”.

With gitmek (to go), tatile gitmek is a fixed, natural phrase meaning:

tatile gitmek – to go on vacation / to go away on holiday

Compare:

tatilde – on vacation (locative, “at/in”)
- Şu an tatildeyim. – I am on vacation now.
tatile – to vacation (dative, direction)
- Yarın tatile gidiyorum. – I’m going on vacation tomorrow.

So in this sentence:

tatile gidebileceğimi = that I can go on vacation.

What is the -ebil- part in gidebileceğimi, and can we leave it out?

The -ebil- is the potential / ability suffix, meaning “can / be able to”.

Breakdown of gidebileceğimi:

git- – go
-e- – vowel inserted for harmony
-bil- – can / be able to → gidebil- = can go
then -ecek (future), -im (I), -i (object), etc. (explained in the next question)

If you remove -ebil-, you get:

gideceğimi sanmıyorum. – I don’t think I will go (on vacation).
gidebileceğimi sanmıyorum. – I don’t think I can go (on vacation).

So:

With -ebil- → about possibility/ability.
Without -ebil- → about likelihood / intention (“won’t go”).

You can leave it out, but then the meaning changes from can/might go to will go.

Why is the verb in the form gidebileceğimi instead of a simpler gidebilirim?

Because in this sentence, “that I can go on vacation” is the object of sanmıyorum (“I don’t think”).

In English:

“I don’t think (that I can go on vacation).”

In Turkish, this “that-clause” is turned into a noun-like form with suffixes:

gidebileceğimi is a noun clause meaning “that I can go”.

Structure:

git- – go
-e-bil- – can / be able to → gidebil-
-ecek – future participle → gidebilecek ≈ “(one) who will be able to go”
-im – 1st person singular (I am the one who will be able to go)
→ gidebileceğim = that I will be able to go / my being able to go
-i – accusative, because this entire clause is the object of sanmıyorum
→ gidebileceğimi

So literally, gidebileceğimi sanmıyorum =
“I don’t think (my being able to go),” meaning
“I don’t think I can go.”

Using gidebilirim would create a full, independent sentence, not an object clause:

Tatile gidebilirim. – I can go on vacation.
Tatile gidebileceğimi sanmıyorum. – I don’t think I can go on vacation.

The second one correctly embeds the idea as the object of sanmıyorum.

What does the final -mi in gidebileceğimi represent?

The last -mi is actually two things fused:

-im – 1st person singular marker (I)
-i – accusative ending (object marker)

Due to sound changes (k → ğ before vowels), the full breakdown is:

git – go
-e-bil – can
-ecek – future → -eceğ when another vowel follows
-im – 1st person singular → gidebileceğim (that I will be able to go / my being able to go)
-i – accusative (marks the whole “that I can go” clause as the direct object)
→ gidebileceğimi

So:

gidebileceğim – subject form: “my being able to go”
gidebileceğimi – object form: “(that) I can go” as the thing I don’t think.

Because sanmak is a transitive verb (“to think / suppose something”), its object must be in the accusative, hence the final -i.

Can we change the word order, or must it be exactly Bavulumu hazırlamadan tatile gidebileceğimi sanmıyorum?

Turkish word order is relatively flexible, but the default is S–O–V (Subject–Object–Verb), and modifiers usually come before what they modify.

Your sentence is already in a very natural order:

[Bavulumu hazırlamadan] – without packing my suitcase (adverbial phrase)
[tatile gidebileceğimi] – that I can go on vacation (object clause)
sanmıyorum – I don’t think (main verb)

Some acceptable variations with slightly different emphasis:

Tatile gidebileceğimi, bavulumu hazırlamadan sanmıyorum.
(Unusual, and sounds off; splitting object and adverbial is not natural here.)
Bavulumu hazırlamadan, tatile gidebileceğimi sanmıyorum.
(Comma after the adverbial; still okay, similar meaning.)

But you cannot move sanmıyorum into the middle:

✗ Bavulumu hazırlamadan sanmıyorum tatile gidebileceğimi. (ungrammatical)
✗ Sanmıyorum bavulumu hazırlamadan tatile gidebileceğimi. (sounds very unnatural, almost like calque from English)

The main verb usually comes last, and the object clause should stay close to the verb. The original sentence is the most natural choice.

Could we also say Bavulumu hazırlamadan tatile gidemem? What’s the difference?

Yes, you can say:

Bavulumu hazırlamadan tatile gidemem.

Differences in meaning/nuance:

Original sentence:
Bavulumu hazırlamadan tatile gidebileceğimi sanmıyorum.
→ I don’t think I can go on vacation without packing my suitcase.
- Emphasizes your opinion/belief (“I don’t think…”).
- Slightly softer, more subjective.
Alternative sentence:
Bavulumu hazırlamadan tatile gidemem.
→ I cannot go on vacation without packing my suitcase.
- A direct statement of inability/impossibility.
- Stronger, more categorical.

So:

sanmıyorum = I don’t think / I doubt it.
gidemem = I cannot / It’s not possible.

Both are correct; they just differ in strength and subjectivity.

Could we use zannetmiyorum or düşünmüyorum instead of sanmıyorum here?

Yes, you can replace sanmıyorum with zannetmiyorum with almost no change in meaning:

Bavulumu hazırlamadan tatile gidebileceğimi zannetmiyorum.
≈ I don’t think I can go on vacation without packing my suitcase.

sanmak and zannetmek are very close in colloquial usage, though some speakers feel zannetmek is a bit more informal.

düşünmek is trickier:

düşünmüyorum literally means “I don’t think / I don’t consider” (as in “I’m not planning” or “I don’t have that idea”).

So:

Bavulumu hazırlamadan tatile gidebileceğimi düşünmüyorum.
Can still be understood as “I don’t think I can go on vacation without packing my suitcase,” but it sounds a bit more like “this idea doesn’t occur to me / I don’t have that thought” than like a judgment of likelihood.

Most natural choices here:

… sanmıyorum.
… zannetmiyorum.

Both correspond very well to English “I don’t think…”.

How would the meaning change if we said gidebileceğini or gidebileceklerini instead of gidebileceğimi?

Changing the person marker changes who is able to go.

gidebileceğimi – I can go
- -im = 1st person singular
- that I can go / that I will be able to go
gidebileceğini – you/he/she can go (depending on context)
- -in / -ı collapsed to -ni → -ğini
- that you can go / that he can go, etc.
gidebileceklerini – they can go
- -leri = 3rd person plural
- -ni = accusative
- that they can go / that they will be able to go

So for example:

Bavulumu hazırlamadan tatile gidebileceğini sanmıyorum.
→ I don’t think *you / he / she can go on vacation without packing my suitcase.*
(Context decides who “he/she/you” is.)
Bavulumu hazırlamadan tatile gidebileceklerini sanmıyorum.
→ I don’t think *they can go on vacation without packing my suitcase.*

The rest of the structure is the same; only the subject of the embedded clause changes.

How would you say “I didn’t think I could go on vacation without packing my suitcase” in Turkish?

You can put sanmak into the past and usually keep the inner clause as it is:

Bavulumu hazırlamadan tatile gidebileceğimi sanmıyordum.
→ I didn’t think I could go on vacation without packing my suitcase.

Breakdown:

sanmıyorum – I don’t think
sanmıyordum – I didn’t think / I was not thinking

So:

Present: Bavulumu hazırlamadan tatile gidebileceğimi sanmıyorum.
Past: Bavulumu hazırlamadan tatile gidebileceğimi sanmıyordum.

If you really want to push the “could” (= past ability), you might also see:

Bavulumu hazırlamadan tatile gidebileceğimi düşünmüyordum.
(also fine, but uses düşünmek instead of sanmak)

The first past form with sanmıyordum is the closest direct equivalent.