Learn Hardcore Arabic (Modern Standard): دفع صديقي القسط بالفعل. - My friend has already paid the instalment.

دفع is a past/perfect verb, third-person masculine singular. In this sentence it means he paid. Arabic does not need a separate helping verb like did here; the single word دفع already tells you that the action happened in the past.

Does دفع only mean paid?

No. دفع can have more than one meaning, including to pay and to push. The object tells you which meaning is intended. Because the object here is القسط meaning the installment, the natural meaning is paid, not pushed.

Why does the sentence start with the verb?

This is a very common Arabic pattern called a verbal sentence: verb + subject + object. So دفع صديقي القسط is a normal way to say My friend paid the installment. Arabic can also use subject + verb order, but starting with the verb is especially common in MSA.

Can I also say صديقي دفع القسط بالفعل?

Yes. That word order is also correct. The version with صديقي first gives a little more focus to my friend, while دفع صديقي القسط بالفعل is the more neutral verb-first structure.