4 sentences

1. 你必须改掉这个坏习惯。

   nǐ bì​xū gǎi​diào zhè gè huài xí​guàn.

   You must break this bad habit.

   Source: Dong Chinese Dictionary

2. 这种奢侈浪费的习惯必须改掉。

   zhè zhǒng shē​chǐ làng​fèi de xí​guàn bì​xū gǎi​diào.

   This habit of luxury and waste must be changed.

   Source: Dong Chinese Dictionary

3. 他下定了决心要改掉这个坏习惯。

   tā xià​dìng le jué​xīn yào gǎi​diào zhè gè huài xí​guàn.

   He has made up his mind to get rid of this bad habit.

   Source: Dong Chinese Dictionary

4. 他下定决心要狠狠改掉这个坏习惯。

   tā xià​dìng jué​xīn yào hěn​hěn gǎi​diào zhè gè huài xí​guàn.

   He is determined to kick this bad habit for good.

   Source: Dong Chinese Dictionary