"We have to go to study."

Translation: हमें पढ़ने जाना है।

[StormMaashrooms]

Is it also allowed to use the long forms of the objective pronouns? Like instead of मुझे, मुझको, or instead of हमें, हमको.

[SyrMja]

yep, interchangeable as far as I know.

[Maheshwara19]

Can we use jaane instead of jaana? Vinay22

[GabrielBou109736]

I don't think so, because "have to" always takes the singular form in hindi, no matter which singular or plural subject is considered: " I have to X to Y । मुझे Y-ने X-ना है" and "We have to X to Y । हमें Y-ने X-ना है" see that the subject that does the action takes को, है is never हैं even if the subject is plural, and one verb takes ने and the other ना : "I have to go (in order) to eat । मैं+को eatने goना है". That's how I get it. We need the pros anyway to be sure XD!