I'm writing to you to response your kindness during my stay in Canada.
It was a good experience that you took me to Naiagara falls which was one of the largest fall in the world.
Also, good dishes you cooked brought me happy.
I would NOT forget you and your kind-heart.
Please let me know when you travel to Japan, I would like to guide you!
Take care of yourseelf and say hello to XX and OO.
I deeply appreciate what you have done for me.
>I'm writing to you to response your kindness
→I'm writing to you to thank you for your kindness
ちなみに"response"は名詞。動詞は"respond"
>Naiagara falls which was one of the largest fall in the world.
→Niagara Falls, one of the largest waterfalls in the world. あえて関係代名詞を使わなくても良いかも。(綴りNaiagara → Niagara)
>Also, good dishes you cooked brought me happy.
→Also good meals you cooked made me happy.
"dishes"はそのままでもいいのかもしれないけど。
>I would NOT forget → I will NEVER forget
"would"ではなく"will"。"never"は「僕なら」ということで。
「Thank you for your modification.」は何が「Thank you」なのかが判らないです。例えば、こちらからの注文数が誤っていて、それを変更して欲しいと言うリクエストを出した場合。こちら側の立場では訂正ですが、相手方の立場では変更です。だから、「注文数を変更しました」というメールへの返事であるなら一応OKだけど、「your modification」というのは何を指しているのか判らないのであまり良くないです。(ビジネスメールでの返事がならただの「Thank you.」でOKですね。)
I have to drink a cup of tea with your finger dirt...(困惑する彼)This means that I really respect you and I have to study much harder as you have done. This expression is from people who work hard at farm. Those who do not work are told to drink their finger dirt and sand so that they can follow their behavior..
もっさんさん。
>I have to drink a cup of tea with your finger dirt
と言われたら「えっ、なにそれ?」と変な顔をされるのは仕方ないですね。僕らも実際に「爪の垢」をお茶に入れて飲むわけでは無いじゃないですか。「私はあなたの爪の垢を入れたお茶を飲まなきゃならない」なんて、本当にそうするみたいですよね。要はこれは『比喩』な訳なので;
We say like this, "......" in Japan.
「日本ではこんな風に言います。『〜』」という風に言うと良いと思います。
ところで「〜を煎じて飲む」って、難しいですね。"extract"でいいのかな?
"We/I/You need to have tea extracted from your finger dirt."
なんてどうでしょう?