after behind
after多用于表示顺序的前后，如：She walked in the line after Tom. 或用来表示"追赶"，表示一种动态，如：He ran after Mary. 而behind多用于强调先进与落后，如：She is much behind the other girls in sewing. 或者用于表达"迟于"，如：The train was ten minutes behind the time table. 或者与表示静态的动词连用，如：She hid herself behind the flowers.
afternoon
［误］ He worked very hard in a hot afternoon.
［正］ He worked very hard on a hot afternoon.
［析］ 习惯用的词组in the afternoon, 如果加入任何修饰词后其前面的介词in都要改为on，不论其修饰词在前还是在后，如：He swam in this river on the afternoon of June lst. 又如：Are you free on Sunday afternoon?
against
［误］ He against me.
［正］ He is against me.
［析］ 要注意against意为"反对"，但它在英文中却不是动词，而是介词，如要讲反对某事或某人时则要加动词be, 如：He is against somebody/something.
against for
against意为"反对"、"不赞成"；而for则意为"同意"，为其反意词。如：Are you for or against the plan?
age
［误］ He is twenty years old of age.
［正］ He is twenty.
［正］ He is twenty years old.
［正］ He is at the age of twenty.
ago
［误］ Tom's father has been dead five years ago.
［正］ Tom's father died five years ago.
［析］ ago意为由说话时算起，若干时间以前。它只能和一般动词过去时连用，而不要与完成时连用。
［误］ Yesterday I met a friend. We didn't see each other for a long time since we left the college twenty years ago.
［正］ Yesterday I met a friend. We hadn't seen each other for a long time since we left the college twenty years ago.
［析］ 要注意的是在本句是ago是用在由since引起的从句之中，只是从句应用过去时，但不影响主句的时态。
agree
［误］ Does the teacher agree to us?
［正］ Does the teacher agree with us?
［误］ Does he agree with our plan?
［正］ Does he agree with us?
［析］ agree with 指"同意某人的提议、建议、计划"等。如果要讲同意某项计划则要用agree to, 如：Do you agree to the plan?
all
［误］ The old man has two sons. All of them are workers.
［正］ The old man has two sons. Both of them are workers.
［析］ all是指三者或以上的全部，而both则是指"两者都"。
［误］ The all children are playing football now.
［正］ All the children are playing football now.
［析］ all作修饰词时其位置要在所有的修饰词之前，不论这些修饰词是定冠词、指示代词、形容词或名词，或代词的所有格。
［误］ You all are right.
［正］ You are all right.
［析］ all作同位语时其位置要置于be动词之后，实意动词之前，如：The teachers all work hard. 或用于第一助动词之后，如：The boys have all been waiting for their mothers.
almost
［误］ Nearly nobody thinks he is right.
［正］ Almost nobody thinks he is right.
［析］ nearly与almost是近意词，其含意差别不大，但是与否定词连用时要用almost, 例如：She brought almost no money with her. 此句中的almost不能用nearly替换。
alone
［误］ The old man lived lone but he didn't feel lonely.
［正］ The old man lived alone, but he didn't feel lonely.
［析］ alone, lone, lonely 三个词全具有"孤单、孤独"之意。但其用法不同：lone可以作定语，而alone则只能作表语，lonely则多指感情上与感觉上的孤独。
already
［误］ We are already for the work.
［正］ We are all ready for the work.
［析］ already 是副词，其意为"已经"，如：He already knew about it. 而all ready为形容词意为"准备好"。
already yet
already多用于肯定句中，例如：The students have already finished the work. 而yet则多用于疑问句与否定句中，如：Have you finished it yet? I haven't finished it yet.
also
［误］ I didn't find the dictionary also.
［正］ I didn't find the dictionary either.
［析］ 作为"也"讲，在否定句中要用either而不能用also.
also too
also与too都可用在肯定句中表示"也"，但also通常用于be动词或情态动词之后，如：I can also do it myself. 而too一般放于句尾。I'll attend his class, too.
always
［误］ Always he asked himself why he had come here.
［正］ He always asked himself why he had come here.
［析］ always一般不能用于句首，它在一般句中的位置是于动词之前第一助动词之后，如：I've always thought he is honest. 又如：He is always late.
among
［误］ If the three apples are divided among the two boys how much will each receive?
［正］ If the three apples are divided among the three boys how much will each receive?
［析］ among常用于三个事物或人物之间，而between则多用于两者之间。
an
［误］ This is an useful dictionary.
［正］ This is a useful dictionary.
［析］ 详见a条。
and
［误］ He did not speak loudly and clearly.
［正］ He did not speak loudly nor clearly.
［误］ Our school is not in New York and Chicago, but in Boston.
［正］ Our school is not in New York or Chicago, but in Boston.
［析］ "和"这一概念在肯定句中应用and，但在否定句中则要用or
