Toplantı bitmişken dosya ekini tekrar kontrol edelim; sonra tahtadaki planı sileriz.

Bitmişken comes from bitmiş + -ken.

• bitmiş = finished / ended
• -ken often means while, but with a completed form like bitmiş, it often means now that / since

So Toplantı bitmişken means something like:

• Now that the meeting is over...
• Since the meeting has ended...

In this sentence, it gives the reason or convenient moment for the next action.

These forms mean different things:

• biterken = while it is ending / as it is ending
• bittiğinde = when it ended / when it has ended
• bitmişken = now that it has ended / since it is already over

Here, the idea is not during the ending of the meeting. The idea is that the meeting is already finished, so this is a good time to do something else. That is why bitmişken fits well.

-ken is a suffix that gives a meaning like:

• while
• when
• as
• sometimes since / now that

Its exact meaning depends on the form before it.

Examples:

• çalışırken = while working
• evdeyken = while at home
• hazırken = while ready / since it is ready
• bitmişken = now that it is finished

So -ken is flexible, and in this sentence it clearly has the sense of now that / since.

Kontrol edelim means let’s check.

The ending -elim / -alım is the 1st person plural optative/cohortative, which is used for suggestions involving we:

• gidelim = let’s go
• bakalım = let’s see
• kontrol edelim = let’s check

So this is not just a plain present tense. It is a suggestion: Let’s check the file attachment again.

Kontrol etmek is a very common Turkish verb phrase built from:

• kontrol = control/check/inspection
• etmek = to do

Turkish often uses noun + etmek to form verbs, especially with borrowed nouns.

So:

• kontrol etmek = to check / to inspect
• yardım etmek = to help
• iptal etmek = to cancel

In everyday Turkish, kontrol etmek is completely normal and natural.

This is one of the most important grammar points in the sentence.

Dosya eki means file attachment.

It is a noun compound:

• dosya = file
• ek-i = its attachment / attachment of the file

In Turkish noun compounds, the second noun often gets a 3rd person possessive ending:

• dosya eki = file attachment
• telefon numarası = phone number
• masa lambası = table lamp

Then, because this whole noun phrase is the definite direct object, it also takes the accusative:

• dosya eki = file attachment
• dosya ekini = the file attachment

Breaking it down:

• ek-i = attachment of the file
• ek-i-n-i = the file attachment (as definite object)

That extra n appears before the accusative after a possessive ending.

Because both are definite direct objects.

In Turkish, a specific direct object usually takes the accusative:

• kitap okudum = I read a book / books
• kitabı okudum = I read the book

So here:

• dosya ekini = the file attachment
• planı = the plan

These are both specific, known things, so accusative marking is expected.

Tekrar means again.

Here it modifies kontrol edelim:

• dosya ekini tekrar kontrol edelim = let’s check the file attachment again

Its position is quite natural here, but Turkish word order is flexible. You may also hear:

• tekrar dosya ekini kontrol edelim
• dosya ekini kontrol edelim tekrar (less neutral in many contexts)

The version in the sentence is very standard.

Tahtadaki means the one on the board or the one that is on the board.

It comes from:

• tahta = board
• tahtada = on the board
• tahtadaki = the one on the board / the thing on the board

The suffix -ki can turn a location phrase into something adjectival.

So:

• tahtadaki plan = the plan on the board

This is a very common pattern:

• masadaki kitap = the book on the table
• dolaptaki tabaklar = the plates in the cupboard
• bahçedeki kedi = the cat in the garden

Because these are two different structures.

Dosya eki is a noun compound:

• file + attachment

But tahtadaki plan is:

• plan modified by the adjective-like phrase tahtadaki

So tahtadaki describes which plan:

• the plan on the board

There is no compound relationship like file attachment here. It is just plan with a modifier.

This is a very natural contrast in Turkish.

• kontrol edelim = let’s check
  This is a direct suggestion.
• sonra tahtadaki planı sileriz = then we’ll erase the plan on the board
  This sounds like the next step in the plan.

So the first clause is an invitation/suggestion, while the second sounds more like:

• then we can erase it
• then we’ll erase it
• then we erase it

If the speaker wanted both parts to sound like equal suggestions, they could also say:

• Toplantı bitmişken dosya ekini tekrar kontrol edelim; sonra tahtadaki planı da silelim.

That would mean: ...then let’s erase the plan on the board too.

Literally, sileriz is the aorist form of silmek for we.

The Turkish aorist can express different ideas depending on context:

• habitual action
• general truth
• willingness
• planned next step
• a softer future-like meaning

In this sentence, with sonra (then/afterwards), it most naturally means something like:

• then we’ll erase
• then we can erase

So although it is not the same as sileceğiz, it can sound future-like in context.

You could say sileceğiz, but the tone changes a little.

• sileceğiz = more explicitly we will erase
• sileriz = more natural, matter-of-fact, and a bit softer in planning/sequencing contexts

In everyday Turkish, sileriz can sound like:

• we’ll erase it then
• we can erase it then
• then we just erase it

So sileriz feels smooth and conversational here.

Very natural.

The sentence is organized like this:

• Toplantı bitmişken = context/background
• dosya ekini tekrar = object + adverb
• kontrol edelim = main action
• sonra = then
• tahtadaki planı = object
• sileriz = verb

This fits normal Turkish word order well, especially with the verb at the end of each clause.

Turkish does allow movement for emphasis, but the version here is neutral and natural.

Ek is a common word meaning:

• addition
• appendix
• attachment
• suffix

The exact meaning depends on context.

Here, with dosya, it means attachment, especially something like a file attached to a message or document.

So dosya eki is best understood as:

• file attachment

Do not confuse this with ek meaning a grammatical suffix, although it is the same word.

Not grammatically essential, but it helps organize the sentence.

It separates two closely related actions:

1. Let’s check the file attachment again
2. Then we’ll erase the plan on the board

A comma could also work in many contexts, but the semicolon makes the pause and separation a little clearer in writing.