Source: Swan. M. 2005. Practical English Usage Oxford, United Kingdom: Oxford University Press (2011).
Practical English Usage lists over a hundred common mistakes in the English language. Listed below are a number of mistakes that intermediate students of English often make according to Swan (2005).
“Although it was late, but she went out.” = Although it was late, she went out.
(511.1) One conjunction is enough to join two clauses – we do not normally use two. However, we can use and or or together with a repeated conjunction.
“You have better to see the doctor.” = You had better see the doctor.
(230.2) Had better refers to the immediate future, but the form is always past (have better is impossible). After had better we use the infinitive to.
“I use to play tennis at weekends.” = I play tennis at weekends.
(604.2) Used to … has no present form (and no progressive, perfect, infinitive or -ing forms). To talk about present habits and states, we usually just use the simple present tense.
“It can rain this evening.” = It may/might/could rain this evening.
(345.3) To talk about the chance (possibility) that something will happen, or is happening, we use may, might or could, but not can. Might and could suggest a less strong possibility.
“My parents wanted that I study.” = My parents wanted me to study.
(283) Many verbs are followed by object + infinitive. With some verbs (e.g. want, allow), a that-clause is impossible.
“You must stop to smoke.” = You must stop smoking.
(299.12) Some verbs that are followed by -ing forms can also be followed by an infinitive of purpose. A common example is stop. E.g. I stopped running; I stopped to rest.
“I look forward to see you.” = I look forward to seeing you.
(298.2) To is actually two different words. It can be an infinitive marker, used to show that the next word is an infinitive (e.g. to swim, to laugh). It can also be a preposition, followed for example by a noun (e.g. She’s gone to the park, I look forward to Christmas). When to is a preposition, it can be followed by the -ing form of a verb, but not normally by the infinitive.
“I’m boring in the lessons.” = I’m bored in the lessons.
(409.2) Interested, bored, excited, etc say how people feel. Interesting, boring etc describe the people or things that cause the feelings.
“He has much money.” = He has a lot of money.
(357.1) Much is used with singular (uncountable) nouns. (333.2) There is not much difference between a lot of and lots of: they are both used mainly before singular uncountable and plural nouns.
See other: Notes On English Grammar