〜ている (Teiru) vs 〜てある (Tearu) vs 〜ておく(Teoku)
Learning to differentiate the subtle nuances between 〜ている, 〜てある, and 〜ておく might be one of the biggest headaches for Japanese learners. Not only do they look similar, but they can all serve a similar purpose, too: these grammar patterns describe a situation created by some intentional action done in the...