This is the 3888th most frequent Russian word.
будут
"Будут" means "will be" in English.
The word "будут" is used as the auxiliary verb to indicate future tense for the verb "идти" (to walk).
Они будут идти пешком в парк.
They will be walking to the park on foot.
The word "будут" is used as part of the future tense question about having classes, with "занятия" indicating activities.
Будут ли у нас завтра занятия?
Will we have classes tomorrow?
The word "будут" is used to describe the future condition of "условия" (conditions), acting as the auxiliary verb.