Learn Hardcore Turkish: Misafirim gelmeden çarşafları yıkayıp serdim. - Before my guest arrived, I washed the bedsheets and laid them out.

As a standalone predicate, misafirim means “I am a guest.”
Here it precedes gelmeden, so it’s a possessed noun meaning “my guest” and serves as the subject of the subordinate action.
A quick test: if the word is doing something (e.g., misafirim gelmedi), it must mean “my guest,” not “I am a guest.”
You can add benim for emphasis: benim misafirim = “my guest,” but benim is optional.

Why does gelmeden have the negative -me if the meaning is “before (my guest) came,” not “without coming”?

The converb -meden/-madan (negative + ablative) commonly expresses “before V-ing” relative to the main clause’s time.
It can also mean “without V-ing,” depending on context. In this sentence, the natural reading is temporal: “before.”

Can I say gelmeden önce or gelmezden önce instead? Any nuance?

gelmeden önce is fully natural and makes the “before” meaning explicit.
gelmezden önce is more formal/literary; you’ll see it in writing more than speech.
gelmeden alone is also fine; adding önce is often stylistic or to avoid any potential “without” reading.

Could gelmeden here mean “without my guest coming”? How would I force that reading?

It could in a context that supports it, but not naturally in this sentence.
To force “without,” you can add adverbs or use -meksizin: Misafirim hiç gelmeden ayrıldım / Misafirim gelmeksizin ayrıldım = “I left without my guest ever coming.”

Why is çarşafları in the accusative? Could I say çarşaf or çarşaflar instead?

Turkish marks definite/specific direct objects with the accusative: -ı/-i/-u/-ü. You’re talking about specific sheets, hence çarşafları.
çarşaf yıkayıp serdim sounds indefinite/unspecified: “I washed and spread (some) sheets.”
Plural + accusative (-ları) is normal when you mean “the sheets” (a particular known set).

What does -ip do in yıkayıp? Why not just yıkadım ve serdim?

-ip links same-subject actions and implies sequence (“and then”).
yıkayıp serdim is compact and natural. yıkadım ve serdim is also correct, a bit heavier, and more neutral in feel.
You cannot use -ip if the following verb has a different subject.

Why is there a y in yıkayıp?

Buffer y prevents two vowels from clashing: yıka + -ıp → yıkayıp.
The converb follows vowel harmony: -ıp/-ip/-up/-üp; after yıka, the right form is -ıp.

Do I need to repeat the object after -ip? For example, çarşafları yıkayıp serdim onları?

No. The object çarşafları is shared by both verbs. Repeating onları is unnecessary unless you want contrastive emphasis.

Shouldn’t it be past perfect (e.g., yıkamış ve sermiştim) to match English “had washed … had laid”?

Not required. Turkish typically uses adverbs/converbs for temporal relations. With gelmeden, simple past (serdim) is enough.
-mişti (past perfect) is optional for extra emphasis on anteriority or a report-like tone: … yıkamış ve sermiştim. Both versions are grammatical.

Is the word order fixed? Can I move parts around?

Fairly flexible. Natural variants include:
- Misafirim gelmeden çarşafları yıkayıp serdim. (time-setting first)
- Çarşafları misafirim gelmeden yıkayıp serdim. (object in focus)
Keep the main finite verb (serdim) at the end for neutral order.

Where is the explicit “I”? How do I know the subject of the main clause?

The verb ending -m in serdim marks first person singular, so the subject is “I.” Turkish normally drops subject pronouns unless emphasized (Ben … serdim).

Whose action is gelmeden describing? Does it have to be the same subject as the main verb?

It can be a different subject. Here, misafirim (my guest) is the subject of gelmeden, while “I” is the subject of serdim.
Contrast this with -ip, which requires the same subject for the linked verbs.

Can I say misafir gelmeden instead of misafirim gelmeden?

Yes, but the meaning changes:
- misafir gelmeden = “before a/any guest came” (indefinite)
- misafirim gelmeden = “before my guest came” (definite, possessed)
Plural: misafirlerim gelmeden = “before my guests came.”

What’s the difference between gelmeden and gelince?

gelmeden = “before (someone) comes.”
gelince = “when/once (someone) comes.” Using gelince would mean you did the action at the time of the arrival, not beforehand.

Is sermek the right verb with çarşaf? What if I mean “hang to dry”?

Yes. Çarşaf sermek is the standard collocation for laying/spreading sheets on a bed.
If you mean hanging them to dry, use asmak: çarşafları yıkayıp astım.

Can you break down the forms morphologically?

misafir-im: misafir (guest) + 1st person possessive -im = “my guest.”
gel-me-den: gel (come) + negative -me + ablative -den → converb meaning “before/without V-ing.”
çarşaf-lar-ı: çarşaf (sheet) + plural -lar + accusative -ı.
yıka-yıp: yıka (wash) + converb -ip with buffer -y.
ser-di-m: ser (spread) + past -di + 1sg -m.