Learn Hardcore Turkish: Ben gelmeyecektim, ama vardiya değişti. - I wasn’t going to come, but the shift changed.

It’s the future-in-the-past (negative): “I was not going to [verb].” It describes a plan or intention that existed at some point in the past, often one that was later changed or canceled by new circumstances (here, the shift changing).

How is gelmeyecektim formed morphologically?

Suffix order in Turkish verbs is typically: verb stem + neg/ability + tense/aspect + past/report + person.

gel (come)
-me- (negation)
-y- (buffer to avoid two vowels touching)
-ecek (future)
-ti (simple past, making “future-in-the-past”)
-m (1st person singular) Together: gel-me-y-ecek-ti-m → gelmeyecektim.

Why is there a y in gelmeyecektim?

It’s a buffer letter used when a suffix beginning with a vowel follows another vowel (here, -me + -ecek). The buffer prevents vowel collision: me + ecek → mey-ecek.

Why is it -ti- (as in gelecekti) and not -di- after -ecek?

Consonant devoicing: the past-tense suffix -di turns into -ti after a voiceless consonant. -ecek ends in voiceless k, so -di → -ti, giving -ecekti.

What’s the difference between gelmeyecektim, gelmiyordum, gelmedim, and gelmezdim?

gelmeyecektim: I wasn’t going to come (a planned intention at a past time, typically later changed).
gelmiyordum: I wasn’t coming (ongoing past process; no inherent sense of plan/cancellation).
gelmedim: I didn’t come (a simple completed fact).
gelmezdim: I wouldn’t come / I used not to come (habitual or hypothetical).

Do I need the pronoun Ben here?

No. The person is already marked by -m in gelmeyecektim. Adding Ben adds emphasis or contrast (e.g., “I, for my part, wasn’t going to come…”).

Can I change the clause order or punctuation?

You can write: Ben gelmeyecektim. Ama vardiya değişti.
Or: Ben gelmeyecektim ama vardiya değişti.
Comma before ama is common but not mandatory; both styles are acceptable in modern Turkish.

Could I say fakat or ancak instead of ama?

Yes:

ama: neutral, very common in speech and writing.
fakat: a bit more formal.
ancak: formal/literary; can also mean “only/just” depending on context.

Why is it değişti and not değişdi?

Same devoicing rule: the past suffix -di becomes -ti after a voiceless consonant. The root değiş- ends with voiceless ş, so -di → -ti: değişti.

Should it be vardiyam değişti instead of vardiya değişti?

vardiya değişti: “the (work) shift changed” in general; context can imply it’s yours.
vardiyam değişti: explicitly “my shift changed.” Use the possessive if you want to be specific.

How would I say it affirmatively (without negation)?

Change the negative suffix to affirmative:

Ben gelecektim, ama vardiya değişti. (“I was going to come, but the shift changed.”)

Can I use the reported past -miş in the second clause, e.g., vardiya değişmiş?

Yes, with a nuance shift:

vardiya değişti: plain/witnessed past, matter-of-fact.
vardiya değişmiş: hearsay/inference/surprise; you learned it indirectly or after the fact.

Is gelmeyecektim the same as “I wasn’t supposed to come”?

Often it overlaps in meaning, but for “supposed to,” Turkish may also use:

Gelmemem gerekiyordu. (I wasn’t supposed/required to come.)
Gelmem beklenmiyordu. (It wasn’t expected that I come.) Use gelmeyecektim for a plan/intention; use the others for obligation/expectation.

How do I make gelmeyecektim into a question?

Insert the question particle after tense/person:

Gelmeyecek miydim? (Wasn’t I going to come?) Note the separate mi particle, with vowel harmony and spacing.

Could I express the cause more explicitly?

Yes:

Ben gelmeyecektim, ama vardiya değişince geldim. (…when the shift changed, I came.)
Ben gelmeyecektim; vardiya değiştiği için geldim. (…I came because the shift changed.)

Any common spelling/pronunciation pitfalls with gelmeyecektim?

Don’t write gelmiyecektim; correct is gelmeyecektim.
In casual speech you’ll hear gelmiycektim/gelmicektim, but keep gelmeyecektim in standard writing.

Can I use a passive to imply “the shift was changed (by someone)”?

Yes:

Vardiya değiştirildi. (The shift was changed.)
If you want to hint at an unspecified “they”: Vardiyamı değiştirdiler. (They changed my shift.)