Learn Turkish: Bilgisayarım ofiste internete bağlanır. - My computer connects to the internet in the office.

The verb root here is bağlan- (to connect). Because this root has more than one syllable (bağ-lan) and ends in a consonant, it takes the -Ir form of the aorist suffix. Following four-way vowel harmony, the 'a' in the root gives us -ır.

I know the verb bağlamak means to connect. Why is the verb bağlanmak used here?

The -n suffix added to bağla- makes the verb reflexive or passive. While bağlamak means you are actively connecting an object to something else, bağlanmak is used when the subject itself gets connected. Since the computer is connecting itself, we use the root bağlan-.

Why does the word internet take the -e suffix here?

The verb bağlanmak requires the dative case, which shows direction. Just like in English where we say connect to the internet, Turkish adds the direction suffix -e to make internete.

Just to be sure, why is it ofiste and not ofisde?