Learn Italian: Credo che il delfino preferisca l'oceano aperto. - I believe that the dolphin prefers the open ocean.

The phrase credo che (I believe that) expresses an opinion or a personal thought. In Italian, expressing an opinion or doubt triggers the subjunctive mood for the verb in the following clause. Therefore, we use the subjunctive preferisca rather than the indicative preferisce.

Preferire is an "-isc-" verb. How does that affect its subjunctive forms?

Just like in the normal present tense, you must insert -isc- between the verb stem (prefer-) and the ending. For regular -ire verbs in the present subjunctive, the singular endings (I, you, he/she/it) are all -a. Adding the infix to the stem gives us preferisca.

Could preferisca also mean "I prefer" or "you prefer"?

Yes! In the present subjunctive, the io, tu, and lui/lei forms are all exactly the same (preferisca). Because these forms are identical, Italian relies on context or an explicitly stated subject—like il delfino in this sentence—to clarify exactly who is doing the action.

Can I drop the che and just say Credo il delfino preferisca... like we drop "that" in English?