Bir yandan böcek kovucuyu kullandık, bir yandan çadır tentesini kapattık.

The pattern bir yandan ..., bir yandan ... is a common Turkish way to show two actions happening in parallel. In English, depending on context, it can feel like:

• while ... , at the same time ...
• on the one hand ... , on the other hand ...
• meanwhile ...

Here it emphasizes that both actions were being done as part of the same situation: using the insect repellent and closing the tent fly.

Yes, you could say something like Böcek kovucuyu kullandık ve çadır tentesini kapattık, but that would simply mean we used the insect repellent and closed the tent fly.

Using bir yandan ... bir yandan ... adds a stronger sense of doing both things alongside each other or handling two things at once. So the original sentence sounds more vivid and situational.

Because Turkish verbs already show the subject.

In kullandık and kapattık, the ending -k tells you the subject is we. So Turkish usually does not need a separate pronoun like biz unless the speaker wants extra emphasis.

• kullandık = we used
• kapattık = we closed

If you added biz, it would sound more emphatic: Biz kullandık = We used it.

Kullandık comes from the verb kullanmak meaning to use.

It breaks down like this:

• kullan- = verb stem, use
• -dı- = past tense
• -k = we

So kullandık literally means we used.

The same pattern appears in kapattık:

• kapat- = close/shut
• -tı- = past tense
• -k = we

So kapattık = we closed.

Because it is the direct object of the verb and it is specific/definite.

In Turkish, a definite direct object usually takes the accusative ending. So:

• böcek kovucu = insect repellent
• böcek kovucuyu = the insect repellent / the repellent

The ending here is -yu because:

• the word ends in a vowel: kovucu
• Turkish inserts a buffer y
• the accusative vowel follows vowel harmony

So:

• kovucu + -(y)u → kovucuyu

This is because two different things are happening:

1. çadır tentesi is a noun compound
2. the whole phrase is then put into the accusative

First:

• çadır = tent
• tente = awning, canopy, fly
• çadır tentesi = the tent fly / the tent canopy

In Turkish noun compounds, the second noun often takes a possessive-looking ending. So tente becomes tentesi.

Then, because it is a specific direct object, it takes the accusative:

• çadır tentesi
• çadır tentesini

The n is a buffer consonant that appears before the accusative after this kind of ending.

It is a very common Turkish noun compound.

Turkish often expresses X of Y or Y-type X by putting two nouns together:

• first noun: çadır = tent
• second noun: tente = canopy/fly

The second noun gets a compound ending:

• çadır tentesi = tent fly, tent canopy

This is different from simply putting two nouns next to each other in English. In Turkish, this pattern is grammatical and extremely common.

It is basically a descriptive noun phrase meaning bug-repelling thing/substance.

• böcek = insect, bug
• kovucu = repellent / repelling thing

So böcek kovucu means insect repellent.

Only the last word takes the case ending:

• böcek kovucu
• böcek kovucuyu

This is normal in Turkish: in multi-word noun phrases, the case ending usually goes on the final word.

Yes. Kapatmak is a very common verb meaning to close, to shut, to cover, or to turn off, depending on context.

With çadır tentesi, it means something like:

• close the tent fly
• pull the tent covering shut
• cover it with the tent fly

So the exact English wording may vary, but kapatmak is perfectly natural here.

Not completely. Turkish word order is fairly flexible, although some orders sound more natural than others.

The given sentence is natural because it keeps a nice parallel structure:

• Bir yandan böcek kovucuyu kullandık
• bir yandan çadır tentesini kapattık

You could move things around for emphasis, but the original version is smooth and balanced. Turkish often places the verb at the end of each clause, which is exactly what happens here.

This is because the past tense suffix changes its sound depending on the consonant before it. This is part of normal Turkish sound harmony.

The past tense suffix can appear as -dı, -di, -du, -dü, -tı, -ti, -tu, -tü.

Here:

• kullan- ends in a voiced sound, so you get -dık → kullandık
• kapat- ends in t, a voiceless consonant, so the suffix becomes -tık → kapattık

So both forms mean the same kind of thing grammatically; the consonant changes for pronunciation reasons.