for oneself、by oneself、beside oneself、to oneself、of oneself、in oneself有何分別？

(1) for oneself指「為自己」或「自己做」，例如：

Man in ancient times had to do almost everything for himself.

古人幾乎每件事都要自己做。
(2) by oneself指「獨自」，例如：
I did it by myself.
我獨力做那件事情。
(3) beside oneself指「忘我」或「發狂」，例如：

He is beside himself with joy.
他喜歡得發狂。
(4) to oneself指「給自己本身」或「只給自己」，例如：

I kept the secret to myself.
我把秘密藏在心中。
(5) of oneself指「自動」或「自發」，例如：
The door opened of itself.
門自動打開了。
(6) in oneself指「本身」或「本身的性質」，例如：

These substances are not poisonous in themselves.

這些物質本身沒有毒性。
（A Dictionary of Modern English Usage）

run down和run-down有何分別？

(1) run down有太多含義，擇其要者簡述如下：
意為tired and in poor health，指精疲力竭或身體衰弱，例如：

He has been working too hard and feels rather run down.

他工作太辛苦，感到精疲力竭。
(2) 又解作knock somebody to the ground, killing or injuring him，指撞倒在地、撞死或撞傷，例如：

He was run down by a cyclist.
他被一名騎腳踏車的人撞倒。
(3) 再解作cease to operate because of the exhaustion of motive，指（因動力耗盡而）停止運轉，例如：

Your clock has run down. The battery needs recharging.

你的鐘停了，電池需要充電。
(4) 還解作criticise unkindly或belittle，即不客氣地批評或貶低，例如：

He's always running his wife down in front of other people.

他總是在別人面前奚落自己的太太。
(5) run-down也有很多含義，只能簡述其中之一：

解作old and broken or in bad condition，指日久失修或破舊，例如：

This old run-down hotel will be demolished.
這間老舊破爛的酒店將被拆。

pay back是「償還」還是「復仇」？

(1) pay back即repay what you owe，指「償還」，例如：

Will you lend me $1,000? I will pay you back next month.

借我1000元好嗎？我下個月還給你。
(2) pay back指repay someone for a kind act he or she has done，指「回報」，例如：

It was so nice to spend the weekend with you and your family. We'll pay you back when we've got a home of our own.

與你全家度周末，非常愉快。我們有了自己的家後，一定回請你們。

(3) pay back又為punish somebody who has done something bad to you，指「報復」或「懲罰」，例如：

We'll pay them back for their insults one day.

總有一天，我們會報復他們的冒犯。
(4) 再介紹一個與pay back（報復）近似的說法：

pay (a person) back in one's own coin即to treat a person in the way that he or she has treated you，指「以其治人之道，還治其人之身」，例如：

Since she refused to help me, the next time she asks me for a favour I will pay her back in her own coin.

既然她不肯幫我，下次她求我時，我當然也不幫她。

讀者Eva來電郵問，書中寫a shoe shop，但店舖裏有很多鞋，是否應寫shoes shop？

Shoe shop是名詞詞組，前面的shoe是名詞修飾語，表示shop的性質。此種情下，shoe毋須加s；同類的例子有：orange juice、childcare、animal trainer等。

「I am not up for it.」、「You talked me into it.」、「She is totally into it.」

(1)be up for指「已提出（供考慮）」，有時簡單點說，就是「想要」，例如：

I'm up for a pizza. Anybody want to chip in?

我要一個意大利薄餅，還有誰想要？
（A New Dictionary of American Colloquial Expressions）

因此，I am not up for it可解作：我不想要它。

(2)talk into指「說服」，例如：
He talked me into coming here.
他說服我來這裏。
因此，You talked me into it可解作：你說服我接受此事。

(3)be into指「有興趣」或「入迷」，例如：
You're really into words.
你對詞語可真入迷。
因此，She is totally into it可解作：她對此事完全入迷。

or和and可以互換嗎?

(1) 在英文否定句，或具否定意味的句子中，若逐項否定各個成分，要使用連接詞or，而不能使用連接詞and，例如：

He never smokes or drinks.
他從來不吸煙，也從來不飲酒。
(2) 若用了and，意思會有變，試比較：
Don't drink or drive.
不許飲酒，也不許駕車。
Don't drink and drive.
不許酒後駕車。

go over

(1)I want to go over the contract with my lawyer before I sign it.

簽約之前，我想和律師一起核查一遍。
(2)She went over the floor with a mop.
她用拖把將地板拖乾淨。
(3)The students went over the lesson before the exam.

學生在考試前複習功課。
(4)We painted the flat once. Then we went over it again.

我們把房子掃一遍漆，過後再掃一遍。
(5)I am going over to Mary's house.
我打算造訪瑪莉的家。
(6)Many of the natives on the island went over to Christianity after the white people came.

白人來到之後，島上很多土著改信了基督教。
(7)The play went over well.
那部戲大受歡迎 [演出很成功]。
(8)This demonstration will never go over with the Conservative Party.

保守黨決不會贊成這種示威遊行。

popularise、impart、propagate三字有何分別？

此三字均可解作「推廣」，但含義和用法略有不同：

(1)popularise可用於物質或精神上的事物，例如：

We are arranging an exhibition to popularise the new types of cars.（物質）

我們在籌備一個展覽會，以推廣新式汽車。
We should popularise scientific notions.（精神）

我們應該推廣科學觀念。
(2)impart本意為「傳授」，可引伸為「推廣」知識、技術等，不可用於物質性的事物，例如：

It was the engineers of that auto company who imparted this new technique to us.

向我們推廣這項新技術的是該車廠的工程師。
(3)propagate本意為「繁殖」或「傳播」，可引伸為「推廣」經驗、技術等，例如：

We'll invite him to come here and propagate the application of their experience.