A lecture was being given to the students A. verb B. noun C. adj

a - - article (a, an, the, some)

lecture - - noun (person, place, thing or idea)

was - - verb (an action or state of being)

being - - verb (an action or state of being)

given - - verb (an action or state of being)

to - - preposition (describes a relationship between the lecture being given and the students)

the - - article (a, an, the, some)

students - - noun (person, place, thing or idea)