Several robbers broke into Mr. Chen's house last night.

Several robbers broke into Mr. Chen's house last night.

Last night, several robbers broke into Mr. Chen's house.

Explanation: Because the adverbial of time was last night, it happened last night, so the verb should be changed into the past tense accordingly, and the original form can no longer be used (indicating the present behavior). The past tense of break is irregular change, not broke.