Rewrite the sentence using appropriate grammatical constructions.
He done his job, but he could have done better.
He did his job, but he could have done it better.
Complete the following task based on the instruction and optional input provided.### Instruction:
Rewrite the sentence using appropriate grammatical constructions.

### Input:
He done his job, but he could have done better.

### Output:
He did his job, but he could have done it better.