問：以下第二句upgrade一字之後，要不要加受詞（object）？──We cordially invite you to upgrade your seats to first class. Simply upgrade to first class at any of our branches（謹請閣下將座位改為頭等，手續可於敝公司任何分行辦理）。
答：Upgrade（晉升）作及物（transitive）或不及物（intransitive）動詞都可以，所以其後不一定要受詞，例如：An MPhil student with excellent research results may upgrade to a doctoral course（哲學碩士課程學生，研究成績卓越者，可升上博士班）。這一句的may upgrade to，假如改為may be upgraded to，那upgrade就是作及物動詞。兩個用法都正確。
不過，讀者示下那兩句，重複使用upgrade to first class四字，畧嫌累贅，或可改寫如下：We cordially invite you to upgrade your seats to first class, which may be done at any of our branches。
問：My birthday is on 1 January（我一月一日生日）這一句，那on字要不要刪去？
答：這一句用不用on都正確，但不用on者似乎較為常見。例如："When is your birthday?" "My birthday is (on) the day before Halloween."（「你那一天生日？」「我是萬聖節之前一天出世的。」）不過，以下第一句的on不應刪去：It is my birthday on 10 October. Would you like to come to my birthday party?（十月十日是我生日，來參加我的生日會好嗎？）