彼(かれ)等(ら) kareraは wa作(さ)業(ぎょう) sagyouを o終(お)え()て() oeteしまった shimatta。 They finished the work. Literal They [topic-は] work [object-を] finished [completely-てしまった]. 終えてしまった uses ~てしまう to mark completion — here without regret, simply indicating the work is fully done. work~てしまう (regret/completion)
彼(かれ)等(ら) kareraは wa作(さ)業(ぎょう) sagyouを o終(お)え()て() oeteしまった shimatta。 They finished the work. Literal They [topic-は] work [object-を] finished [completely-てしまった]. 終えてしまった uses ~てしまう to mark completion — here without regret, simply indicating the work is fully done. work~てしまう (regret/completion)