完了時制 -- When do I use them?

One thing that is useful to realize is that perfect tenses (完了時制) generally work by the same logic.

• logic 論理｛ろんり｝、論理学｛ろんりがく｝、論法｛ろんぽう｝、ロジック、道理｛どうり｝、理詰め｛りづめ｝、理屈｛りくつ｝I see the logic in all that. : その理屈は分かります。It's your logic. : それはあなたの考えだ。(definition from 英辞郎 on the web)

Look at the diagram on the right. When we use a perfect tense, it means that an event has a relationship to some time after the event happens. Can you add something to the diagram to show which time the verb with the perfect tense is related to? I'll update the diagram tomorrow.

I had planned to put an interesting photo with today's post, but I didn't manage to take any good pictures today. <- past perfect

Instead, I have made this diagram. <- present perfect

I hope you will have solved the question about the diagram by tomorrow night. <- future perfect

It was really hot today, wasn't it? I took my rain suit with me because I had expected it to rain. However, it just made my backpack heavier, which made me sweatier. I hope nobody noticed. I haven't figured out how to make my backpack lighter. It's tough having to carry around a portable office all of the time.

• sweaty 汗の出る、汗にまみれた、汗が出るほどの、汗まみれの、汗のような、汗臭い I'm all sweaty. : 汗びっしょりだ。

Can you match the perfect tense sentences in the paragraph above to the diagram? More tomorrow...