This article discusses some of the general difficulties that non-native speakers have with English.  It does not go into detail about how to deal with these problems (for that, you'll want to look at one of the many ESL sites on the Internet).  However, the notes below may help to give English-language learners a better understanding of how the language works (and how it may differ from their native language).

► Perhaps you have noticed that you cannot always use the English word that seems to match a word or phrase in your native language, according to the dictionary definition.  This is because many words in English have multiple meanings (sometimes very different meanings) that change according to context.  (Context = the surrounding words and their meanings.)  For example, the first definitions of give in most diictionaries are likely to be something like "to make a present of, to place in someone's hands, to deliver."  However, when we say that "the audience gave [past tense of give] the singer a round of applause" or "the cold weather gave me chills" or "he gave a cry of terror," we are not talking about give in this sense but using another meaning of the word.  Conversely, we can't say that the audience placed the applause in the singer's hands, that the cold weather delivered chills, or that he placed a cry of terror in someone's hands.  Literal translation often does not make sense.

► Nowhere is this dependence on context more confusing than with English prepositions.  These connecting words, which show relationships between thoughts, usually have many meanings.  The preposition in, for example, often refers to containment ("His coat is in the closet") – but not always.  "He is in love" does not mean that love "contains" him but that he is experiencing love.  "He paid in cash" has nothing to do with containment; it means he paid by using cash (rather than, say, a credit card).  "It was split in two" means that it was divided into two parts.  The same variations in meaning (notice:  another use of in).  This wide variation of meanings in context occurs with almost all English prepositions, not just with in.  Native speakers understand this differences almost automatically.  You will need to learn them mostly by listening and reading because there are not many rules that can guarantee that you're using the correct preposition.

Another problem with prepositions is that some are interchangeable in certain contexts, but they are far from completely interchangeable.  For example, "to be on time" and "to be in time" have approximately the same meaning (to arrive when expected).  However, on and in cannot always (or even often) be used interchangeably.  We can say that someone is in love, but saying that someone is on love makes no sense.  Even more significantly, with respect to location, on and in have different meanings.  Something that is on the dresser is not in it, and something that is in the dresser cannot be on it.

► Context is also important with idioms.  Although there are several definitions of idiom, what we sometimes mean by an idiom is a group of words that, used together, have a different meaning than what the words literally mean.  Idioms may be common phrases such as "to take a shower" (which doesn't mean that we pick up the shower and take it somewhere but that we get into the shower) or "to be under the weather" (which means to feel sick and has nothing to do with being under anything and doesn't relate to the literal meaning of weather).  A considerable amount of slang is idiomatic – so much so that, if we take the separate words literally, what the slang expression says may be ridiculous.

► Speaking of slang, here's a note of caution to English learners.  In your effort to speak naturally (that is, like a native speaker), you may develop a considerable slang vocabulary – derived perhaps from English-language movies or the words of pop songs.  Be very careful.  The way a character speaks in a movie (or the words of a song) may not be correct or even acceptable.  It could be profane (rude) or appropriate only in certain circumstances.  It may not be the kind of language that you want to use in the office, in polite company, or among strangers.  You probably cannot speak natural-sounding English without using some idioms, but be very certain that you know what a slang expression means and where it is appropriate before you make it part of your English vocabulary (no matter how often you hear it from native speakers).  Remember that some native speakers do not speak very well either.  You don't want to follow bad examples.

► Mastering English verbs can also be challenging for non-native speakers.  Your first job is to understand the tenses and how they are use (our guide to English Verb Tenses may be helpful), but this is not enough.  Once more, students of English as a second language must learn some concepts that native speakers take for granted.  For example, the present tense, normally used for describing action that is taking place at the present time, may be used to describe something that will take place in the future, as in, "I go [present tense] back to school tomorrow."  One could also say, "I shall/will go [future tense] back to school tomorrow," but the present tense is also possible and correct.  To complicate matters further, we also have the option of using the present perfect tense, "I am going back to school tomorrow."  It is not unusual for English to offer several ways to express the same idea, all of them correct.

However, I have observed by listening to non-native speakers that they tend to make English verbs more complicated than they need to be – that is, they tend to use verb phrases with several auxiliary verbs when a simple verb is sufficient.  For example, they might say, "i was finishing my homework early" (past progressive) when what they mean is "I finished my homework early" (simple past tense).  A good guideline to follow is to select the shortest form that accurately reflects when the action took place.  Reserve use of the progressive tense for denoting only action that is continuous (ongoing).

These few pointers are those that occur to me at the moment.  If I think of more, I will either add them here or create a second set of guidelines.  I also encourage learners of English as a second language to post questions (general or specific) on the ESL Discussion Board.  (Registration is required, and instructions for reggistering are on the General Message Board page.)