One of the most common mistakes I see among English learners is to say "interesting" instead of interested. For example, I am interesting in learning xxx. It should be "I am interested in learning xxx".
The same goes for boring and bored. If you say "I am boring", it doesn't mean that you don't have anything to do, but that you are not an interesting person!
Another common mistake is not to use capital letters when necessary. It may not seem important to you but it will make your written English look so much better if you use capital letters correctly. Always use capitals for: the first letter of the first word of the sentence, the word "I", languages, countries, cities, names, days of the week, months of the year, names of books and songs.
Maybe other people could add to this.
Another common confusion is the difference between "live" and "living".
I live in China. = China is the permanent place where your home is.
I"m living in China. = You are in China for a temporary stay.
I see a lot of people typing 'u' instead of 'you'. The only times this is acceptable is when texting or when you're in a private IM chatroom (ie. when space is limited and you need to type quickly). If you're sending an email or typing a letter, it's not acceptable.
Another mistake I see often is incorrect word order in adverbial clauses. People often phrase adverbial clauses as questions, and it really sticks out. The following sentences are wrong:
"I don't know when is it."
"Can you tell me what is it?"
"Please explain when does (something) mean (something else)."
Kara, there's a little trick you can do to figure out which article to use. Your English is already good, so you probably don't need it; but I'll write it anyway so other people can see it.
The use of 'the' is similar to 'it'. To figure out what article to use, look at what happens if you replace a noun with 'it':
<em>"There was a dog. The dog was hungry."</em>
<em>-If 'the dog' is replaced by 'it', 'it' is still clearly referring to the dog. Therefore 'the dog' uses the definite article.</em>
<em>-If you replace 'a dog' with 'it', readers won't be able to guess that you're talking about a dog and will just be confused. Therefore, the indefinite article is used.</em>
<em>-Here, you can say 'the dog' or 'it' interchangeably; because 'it' is obviously the dog. The reason why definite articles are used will be made clear in the following example.</em>
"There was a dog, cat and snake. The dog was hungry."
<em>-If 'the dog' is replaced with 'it', 'it' could refer to the dog, cat or snake. Readers could guess that 'it' is the dog; but 'it' could also be the cat or snake. It's unclear what 'it' refers to, so therefore the sentence is poorly written. Since 'it' </em>could<em> refer to the dog, the definite article is used.</em>
"There was a dog, cat and snake. A dog was hungry"
<em>-Readers would interpret this to mean that there are two dogs: one was with the cat and snake, and the other was hungry. Technically speaking, the second dog </em>could<em> be the first one; but it could also be any other dog in existance and people would interpret it as such. It's best just to write 'another' to be clear.</em>
I find all of these comments really interesting. I have to admit that I'm not an English teacher and I never really learnt English grammar so I don't know how to explain it myself, but it seems to me that the main problem is moving away from a word for word translation and towards a native like fluency.
I think that this requires two things: firstly just learning to use the set phrases as they are, and secondly having massive and smart exposure to the language. I've read quite a lot about language acquisition, and to me the method that makes the most sense is to learn chunks of language, rather than individual words. I've seen it discussed in various places, and in particular on a site called Antimoon. They combine vocabulary learning in sentences with spaced repetition software.(This will help yueer-19)
Personally, I'm trying to improve my Hebrew and I'm using the Antimoon method (well, my homemade version of it). Sometimes there are words that I know but would never have thought of using them together. These combinations go into my learning materials. Also every time I learn a new word I google it to see how it is used in different contexts, and I make a learning card of the word and the sentences.
Hope this helps
1. Another mistake is to say something like, "I'm learning the Russian language" or "I want to practice the Russian language".
Technically they may not be grammatical mistakes, but a native speaker would say, "I'm learning Russian", "I want to practice speaking Russian" or "I want to practice my Russian".
2. Non native speakers sometimes say, "I learn Russian". A native would say, "I'm learning Russian".
3. Ditto: "practice my oral English". Native, " practice speaking English".
I think that one of the things that is hard in learning English is that something can be grammatically correct, but it just doesn't sound right.