Learn Spanish (Latin America): Ustedes usarían el helicóptero para viajar a la isla. - You all would use the helicopter to travel to the island.

To form the conditional for regular verbs like usar, you keep the entire infinitive (usar) and add the conditional endings. For ustedes, the ending is -ían, giving us usarían (you all would use). Notice that the endings for the conditional are exactly the same as the imperfect tense endings for -er and -ir verbs!

Why do we use para instead of por before viajar?

In this sentence, para translates to "in order to." When you are expressing the purpose or goal of an action (using the helicopter in order to travel), you always use para followed by an infinitive verb like viajar.

Does ustedes always use the same conditional ending as ellos and ellas?

Yes! Even though ustedes means "you all" (second person plural), it always takes the third-person plural verb endings in Spanish. So, ellos usarían (they would use) and ustedes usarían (you all would use) share the exact same -ían ending attached to the infinitive.

Why does helicóptero have an accent mark on the o?

It has an accent on the o because it is an "esdrújula" word, meaning the spoken stress falls on the third-to-last syllable (he-li-CÓP-te-ro). In Spanish, all words with this stress pattern must have a written accent mark.