Learn Hardcore Turkish: Öğretmen dosyayı buluta yükle dedi; ben de dekontun fotoğrafını aynı klasöre ekledim. - The teacher said to upload the file to the cloud; I also added a photo of the receipt to the same folder.

Turkish often reports direct commands by quoting the imperative and then adding dedi (said): literally “he said ‘upload (it)’.” It’s a natural way to convey what someone told you to do.
If you want an indirect/reported version (closer to “told me to upload”), you typically use a verbal noun and söyledi/istedi:

Öğretmen dosyayı buluta yüklememi söyledi/istedi. = “The teacher told/asked me to upload the file to the cloud.”

Could I make the command plural or more polite?

Yes. Change the imperative form:

Singular/informal: yükle
Plural/formal: yükleyin
Examples with direct quote style:
Öğretmen dosyayı buluta yükleyin dedi. (to a group / politely to one person)

What does ben de mean, and how does de/da work here?

Ben de means “I also / me too.” Here de is the additive particle “also/too,” written separately and obeying vowel harmony: de after front vowels (e, i, ö, ü), da after back vowels (a, ı, o, u).
It attaches to the word it emphasizes. Ben de emphasizes the subject “I” (I, too, did this).

What’s the difference between the particle de/da and the locative suffix -de/-da?

The particle de/da (“also/too”) is written separately: ben de, onlar da.
The locative is a suffix meaning “in/at/on” and is attached: evde (at home), okulda (at school).
They look similar but the particle is separate and unstressed; the locative is a bound suffix.

Why is dosyayı in the accusative?

Because it’s a specific, definite direct object. In Turkish, definite/specific objects take the accusative:

dosyayı = “the file” (that particular file)
If the object were non-specific/indefinite, you’d often leave off the accusative or use bir:
dosya yükledim = “I uploaded a file / file(s) (unspecified).”

Why is it buluta (dative) and not bulutta (locative)?

The verb yüklemek (to upload) involves direction/goal, so you use the dative -a/-e: buluta = “to the cloud.”
The locative -da/-de would mean “in/on/at the cloud,” which doesn’t fit a motion/target meaning.

Why does the case suffix go on klasör in aynı klasöre, not on aynı?

Adjectives in Turkish (like aynı, “same”) don’t take case; the noun they modify does. So the dative attaches to klasör:

aynı klasöre = “to the same folder”
aynı klasörde = “in the same folder”

How does dekontun fotoğrafını work morphologically?

It’s a genitive–possessive construction plus accusative on the possessed noun:

dekont-un = “of the receipt” (genitive)
fotoğraf-ı = “its photo” (3rd person possessive)
fotoğraf-ı-nı = accusative on a possessed noun; the n is a buffer consonant
Whole chunk: dekontun fotoğrafını = “the photo of the receipt” as a specific direct object.

Why is there a buffer y in dosyayı but not in buluta?

When a suffix beginning with a vowel attaches to a word ending in a vowel, Turkish inserts a buffer consonant (usually y):

dosya + ı → dosya-y-ı = dosyayı
Bulut ends with a consonant, so no buffer is needed:
bulut + a → buluta

What does dekont mean, and how is it different from fiş or makbuz?

dekont: a receipt/confirmation usually tied to a bank payment or transfer (proof of payment).
fiş: a till receipt, e.g., from a store or supermarket.
makbuz: a formal receipt acknowledging payment (often more official).

Can I put de elsewhere to mean “also,” and does it change the emphasis?

Yes; de/da follows the word it emphasizes:

Ben de dekontun fotoğrafını ekledim. = I also did it.
Ben dekontun fotoğrafını da ekledim. = I also added the photo (as well as something else).
Ben dekontun da fotoğrafını ekledim. = I added the photo of the receipt too (as well as, say, another document’s photo).
Ben dekontun fotoğrafını aynı klasöre de ekledim. = I added it to the same folder too (as well as elsewhere).

Is the semicolon necessary? Could I use a comma or ve?

A semicolon neatly links two closely related independent clauses. You could also write:

Öğretmen ... dedi, ben de ... ekledim.
Öğretmen ... dedi ve ben de ... ekledim.
All are acceptable; punctuation choice is stylistic here.

Can I specify that the teacher said it to me?

Yes, add an indirect object like bana:

Öğretmen bana “dosyayı buluta yükle” dedi. Word order is flexible, but bana usually appears before dedi (often right after the subject or before the quoted command).

How is dedi different from söyledi? Could I use dedi ki?

demek (dedi) is used for direct quotes: imperative + dedi is very common.
söylemek (söyledi) prefers indirect content with nominalization: yüklememi söyledi.
dedi ki introduces a quoted or paraphrased clause and is also fine:
Öğretmen dedi ki: dosyayı buluta yükle.

Any pronunciation tips for öğretmen and fotoğrafını?

ğ (soft g) doesn’t make its own hard sound; it lengthens or glides the preceding vowel.
öğretmen: the öğ is a lengthened “ö,” roughly “öö-ret-men.”
fotoğrafını: the o before ğ lengthens: “fotoo-raf-ını.”
Also note the dotless ı in aynı and fotoğrafını: it’s a back, unrounded vowel (not like English “i”).

Why no apostrophe in buluta, but sometimes I see apostrophes like Drive’a?

Turkish adds an apostrophe before suffixes on proper nouns: Google Drive’a, Ankara’ya.
Common nouns do not take an apostrophe: buluta, klasöre.

Can you break down the key forms in this sentence?

Öğretmen = teacher.
dosyayı = dosya + -(y)ı (accusative; specific object).
buluta = bulut + -(y)a (dative; destination).
yükle = imperative 2nd singular of yüklemek.
dedi = di- (past stem of demek) + -di (past).
ben de = I + also (particle).
dekontun = dekont + -(n)un (genitive).
fotoğrafını = fotoğraf + -(s)ı (3sg possessive) + -(n)ı (accusative; buffer n).
aynı klasöre = aynı (adj) + klasör + -(y)e (dative).
ekledim = ekle- (add) + -di (past) + -m (1sg).