"I'll finish it by the end of this weekend." he said
→He said (that) he'd finish it by the end of that weekend
*Câu tường thuật với Statements:S+Said+(that)+S+V(lùi về 1 thì)
*Trong đó:Câu trực tiếp:Will→Câu gián tiếp:Would
Câu trực tiếp:This→Câu gián tiếp:That
@TriLeCongTri