by
(1) 用法：by + Ving (一個動作)
e.g. I turn on the computer by pushing the on button. 我按下開機鍵來打開電腦。
e.g. I keep healthy by exercising. 我藉由運動維持健康。
e.g. I learned Karate by watching Youtube. 我藉由看Youtube影片學空手道。
(2) 用法：by + 名詞 (person, place, thing)
e.g. I will contact you by e-mail. 我會用電子郵件聯絡你。
e.g. I will message you by text. 我會傳簡訊給你。
e.g. I will go by bus. 我會搭公車去。
e.g. I came by car. 我搭車來的。
with
用法：with + 名詞 (body parts, tools, instrument)
e.g. Italians talk with their hands. 義大利人說話時手勢非常多。
e.g. I point with my fingers. 我用手指。
e.g. I cleaned the floor with a map. 我用抹布清理地板。
e.g. I ate dinner with a fork. 我用叉子吃晚餐。
