Misafirler gelince, fotoğrafçı aile fotoğrafını çekecek.

Gelince is built from the verb stem gel- (to come) plus the suffix -ince. This form creates a time clause meaning when, once, or after someone comes.

So:

• gel- = come
• gelince = when/once (someone) comes

This is a very common Turkish pattern. English often uses a separate word like when, but Turkish often uses a suffix on the verb instead.

Because gelince is not a full main-clause verb here. It is a subordinate verb form, often called a converb or adverbial verb form. These forms usually do not take the full set of personal endings that ordinary tense forms do.

The subject is shown separately by misafirler (the guests), so misafirler gelince naturally means when the guests arrive.

In this structure, plural meaning comes from the noun misafirler itself. The -ler already tells you the subject is plural.

With -ince clauses, Turkish does not add a separate plural agreement ending to the verb the way an English learner might expect. So misafirler gelince is completely normal.

It can cover a few closely related ideas:

• when
• once
• after

The exact nuance depends on context. In this sentence, it suggests that the photographer will take the family photo when the guests arrive / once the guests have arrived. It does not have to mean the exact instant they walk in.

Yes, you could. Misafirler geldiğinde also means when the guests arrive / when the guests have arrived.

Very roughly:

• gelince often feels a bit more compact and action-sequence-like: when/once they come
• geldiğinde can feel a bit more like at the time when they arrived/have arrived

In many everyday situations, both are possible, but gelince is very natural here.

Çekecek is the future tense.

It is formed from:

• çek- = take, pull, shoot
• -ecek = future suffix

So çekecek means he/she will take or will shoot.

The future suffix appears as -ecek or -acak depending on vowel harmony.

Because in Turkish, fotoğraf çekmek is the normal expression for to take a photo.

Even though çekmek has other meanings too, such as to pull or to draw, with fotoğraf it specifically means to take/shoot a photograph.

So:

• fotoğraf çekmek = to take a photo

This is just the standard Turkish collocation.

Fotoğrafçı means photographer.

It is made from:

• fotoğraf = photograph, photo
• -çı = a person associated with something, often by job, trade, or regular activity

So fotoğrafçı is literally something like photo-person, meaning photographer.

This suffix changes form by vowel harmony:

• -çı
• -çi
• -cu
• -cü

Because Turkish does not have a definite article like English the.

A bare noun such as fotoğrafçı can mean:

• the photographer
• a photographer

Context tells you which one is meant. In a sentence like this, the situation usually makes it clear.

This is a very common Turkish noun-compound pattern.

• aile = family
• fotoğraf = photo
• aile fotoğrafı = family photo

In this pattern, the second noun usually takes an ending that looks like a possessive ending:

• fotoğraf → fotoğrafı

So aile fotoğrafı literally looks a bit like family its-photo, but in natural English it is simply family photo.

This does not always mean literal possession. It is just the standard way Turkish builds many noun combinations of this kind.

Because it is the specific direct object of the verb.

In Turkish, a specific or definite direct object usually takes the accusative ending. So the base compound aile fotoğrafı changes to aile fotoğrafını.

The breakdown is:

• aile fotoğrafı = family photo
• aile fotoğrafı-nı = the family photo, as a definite object

That n is a buffer consonant. It appears because the word already ends with a vowel-containing ending.

Because they have different grammatical roles.

• fotoğrafçı is the subject
• aile fotoğrafını is the definite direct object

In Turkish, subjects are usually in the bare form, with no special ending. Definite direct objects usually take the accusative ending.

So this contrast is very normal:

• fotoğrafçı = bare subject form
• fotoğrafını = object marked with accusative

Yes. Turkish word order is flexible.

This sentence has a very natural structure:

• time clause first: Misafirler gelince
• main verb at the end: çekecek

That gives a neutral, smooth sentence. But other orders are also possible for emphasis, for example:

• Fotoğrafçı, misafirler gelince aile fotoğrafını çekecek.

The main verb usually stays near the end, but other parts can move around more freely than in English.

A few useful points:

• ç = ch as in church
• ı = a vowel English does not really have; it is like a relaxed, back uh sound, but without rounding the lips
• ğ usually is not pronounced like a hard g; it often lengthens or smooths the surrounding vowel instead

So in words here:

• gelince sounds roughly like geh-lin-jeh
• fotoğrafçı sounds roughly like fo-to-raf-chuh
• fotoğrafını sounds roughly like fo-to-ra-fuh-nuh

The biggest trap for English speakers is trying to pronounce ğ as a strong g. In modern Turkish, that is usually not how it works.