Learn Turkish: Plastik çevreye zarar verdiği için onu kullanmıyoruz. - Because plastic harms the environment, we do not use it.

In Turkish, to say "because an action happens," we turn the verb into a describing word using the -dik suffix, add a possessive ending to show who does it, and follow it with için. Here, ver (give) + -dik becomes verdik. We add the 3rd person possessive -i because the subject doing the harming is plastik (it). The k softens to ğ between vowels, making verdiği. Finally, adding için gives us "because it gives (harm)."

Why is the word for environment, çevre, written as çevreye?

The verb phrase for "to harm" in Turkish is zarar vermek, which literally means "to give harm." Just like in English where you give something to someone, this verb requires the dative case (the "to" direction) for the thing receiving the harm. So, we add the buffer letter -y- and the dative ending -e to çevre, making it çevreye (to the environment).

The sentence ends with kullanmıyoruz (we do not use). Why doesn't the -dik part match the "we" subject?

The sentence has two different subjects. "We" are the ones not using the plastic (the main verb kullanmıyoruz), but "plastic" is the one doing the harming. The -dik structure always takes the possessive ending of the person or thing doing that specific action. Since plastic (it) is doing the harming, we use the 3rd person ending on verdiği.