The class started with only two or three students present. (Hint: How)

Class filled up as the minutes went by. (Hint: What)

Summer school was eight weeks long. (Hint: How)

There's a soccer game every night. (Hint: How)

They were on page 36. (Hint: What)

They're studying participles. (Hint: What)

Students are always confused. (Hint: How)

They'll practice a lot. (Hint: How)

They're going to practice the present participle. (Hint: Which)

Eventually the students would grasp it. (Hint: When)