「ありがとうございました」か「ありがとうございます」 I understand -ました is past tense, but I am always confused in which context to use past tense vs. present tense..... When you (or someone else) is leaving work, should it be past or present tense? If you are purchasing something, is it past or present tense? How far into the past must it be for it to be past tense? I get the grammar behind the two. I understand the difference. But it wasn't until living in Japan that the uses for each one stumped me. Explanations (why!) are helpful. Thanks!