Learn Spanish (Latin America): Nos hizo terminar las cien flexiones en la cancha. - He made us finish the hundred push-ups on the court.

With causative verbs like hacer (to make someone do something) or dejar (to let someone do something) followed by an infinitive, the two verbs act as an inseparable team. Because of this, the object pronoun (nos) goes before the conjugated verb (hizo). Unlike regular verb combos like queremos terminar, you cannot attach the pronoun to the end of the infinitive here.

How do we know who is forcing the action and who is actually doing the push-ups?

The conjugated verb hizo (he/she/it made) tells us who is forcing the action. The object pronoun nos (us) tells us who receives that pressure and has to perform the second action, terminar (to finish). Therefore, he made us finish the push-ups.

Why is it cien flexiones instead of ciento flexiones?

You use cien when talking about exactly 100 of something, placed right before the noun. It doesn't change form, even if the noun is feminine (like flexiones). You only switch to ciento for numbers 101 through 199 (for example, ciento una flexiones).

What kind of place is a cancha?

In Latin America, a cancha is a very common word for a sports field or court. Depending on the sport being played, it could mean a soccer field, a basketball court, or a tennis court.