1. Explain it simply
Frame: Subject + 把 + Object + Verb + 了 + complement.
The complement tells how many times (三遍, 两次) or how long (半个小时, 两个小时) the action lasted.
The complement comes after the verb, never before it: say 读了三遍, not 三遍读了.
Keep the object right after 把 and in front of the verb.
2. Show examples
老师把这个句子读了三遍。
Lǎoshī bǎ zhège jùzi dú le sān biàn.
The teacher read this sentence three times.
三遍 counts the action
妈妈把房间打扫了半个小时。
Māma bǎ fángjiān dǎsǎo le bàn gè xiǎoshí.
Mom cleaned the room for half an hour.
半个小时 shows duration
我把这本书看了两遍。
Wǒ bǎ zhè běn shū kàn le liǎng biàn.
I read this book twice.
the complement follows the verb
3. Share a tip
Put the count or duration after the verb: 读了三遍, not 三遍读了.