31. a number of, the number of
a number of許多，謂語動詞用複數。the number of…的數目，謂語動詞用單數。the number of students is increasing.
32. in front of, in the front of
in front of範圍外的前面，in the front of範圍內的前面 in the front of the room sits a boy.
33. of the day, of a day
of the day每一天的，當時的，當代的， of a day暫時的，不長久的 a famous scientist of the day
34. three of us, the three of us
three of us我們（不止三個）中的三個，the three of us我們三個（就三個人）the three of us---tom, jack and i went to the cinema.
35. by bus, on the bus
by bus表手段，方式，不用冠詞，on the bus表範圍 they went there by bus.
36. for a moment, for the moment
for a moment 片刻，一會兒，for the moment暫時，一時 thinking for a moment, he agreed.
37. next year, the next year
next year將來時間狀語，the next year過去將來時間狀語 he said he would go abroad the next year.
38. more than a year, more than one year
more than a year一年多，more than one year超過一年（兩年或三年等）
39. take advice, take the(one's) advice
take advice徵求意見，take the advice接受忠告 he refused to take the advice and failed again
40. take air, take the air
take air傳播，走漏，take the air到戶外去，散步 we take the air every day.
41. in a word, in words
in a word總之，一句話， in words口頭上 in a word, you are right.
42. in place of, in the place of
in place of代替，in the place of在…地方 a new building is built in the place of the old one.
43. in secret, in the secret
in secret秘密地，暗自地，偷偷地，一般用作狀語；in the secret知道內情，知道秘密，一般用作表語 my mother was in the secret from the beginning.
44. a girl, one girl
a girl可泛指所有女孩, one girl一個女孩 can one girl carry such a big box?
45. take a chair, take the chair
take a chair相當於sit down坐下，take the chair開始開會