2 sentences

1. 现在的学生周末经常要补课。

   xiàn​zài de xué​sheng zhōu​mò jīng​cháng yào bǔ​kè.

   Students nowadays often have to take extra classes on weekends.

   Source: Dong Chinese Dictionary

2. 我昨天生病没去学校，今天老师帮我补课。

   wǒ zuó​tiān shēng​bìng méi qù xué​xiào, jīn​tiān lǎo​shī bāng wǒ bǔ​kè.

   I missed school yesterday because I was sick, so the teacher is helping me catch up today.

   Source: Dong Chinese Dictionary