”Reply” and ”Response”

"Reply": 回答. 通常是對一件事以文書或通訊形式作出的回應.
Eg.1. 你寫信俾A公司, 問佢一件貨物嘅價錢, 請佢回答. 就用 "Reply".
"Looking forward to your reply by return." - 祈望盡快得到你的回答.
Eg.2. 你打電話 / 寫信俾煲呔曾, 佢覆你電話 / 回信, 就用 "Reply".
"Bo Tie's reply to my call / letter was late." - 煲呔曾好遲先覆我電話 / 回信

"Response": 回應 / 反應. 通常是對一件事作出的反應, 不限於文書或通訊.
Eg.1. 你寫信去投訴某商場廁所勁污穢, 請佢回應 / 作出改進, 就用 "Response".
"I expect your immediate response to this matter."
Eg.2. 你打999嗌救命, 救護員好快嚟到, 將你由塊體操板度救出, 就用 "response".
"The Firemen's response was immediate."