• look up the meaning of an English word you see or hear
• find the English translation of a word in your language
• check the spelling of a word
• check the plural of a noun or past tense of a verb
• find out other grammatical information about a word
• find the synonym or antonym of a word
• look up the collocations of a word
• check the part of speech of a word
• find out how to say a word
• find out about the register of a word
• find examples of the use of a word in natural language 

To be a good dictionary user, however, it is not enough to know what to use the dictionary for. You must also decide which is the best dictionary for any of the purposes listed above. As well as this, you need to be able to find what you are looking for quickly; you need to be sure that you have found what you were looking for; and, most importantly, you need to know when to use your dictionary.

Knowing which dictionary to use

Electronic dictionaries are the best choice for ESL students. Most of them contain native-language equivalents and explanations, as well as definitions and example sentences in English. They can speak the English word to you, and they are easy to carry around. However, they are expensive and easy to lose, so put your name on yours!

A cheaper possibility, if you are going to work at the computer, is to use an online dictionary. A very good one for ESL students is the Longman Dictionary of Contemporary English. Alternatively, if you open Google and type, for example, define: superstitious, you will get a long list of different definitions of superstitious.

A good monolingual dictionary is recommended for students who already have a high standard of English and want to learn about word use.

Finding words quickly

This is a skill that you need to practise. Ask someone to write down 5 words and see how long it takes you to find them. Of course, you will need to know the English alphabet perfectly, so practise this too. Use the guide words at the top of each dictionary page; and keep practising until you can find any word within 10 seconds. You should also practise finding words in your own language in your bilingual dictionary. If you use an electronic dictionary, take some time at home to learn how it works and, again, practise finding words quickly.

Finding the right meaning of an English word

Very often when you look up a new English word, you find that it has more than one meaning. If you are not sure which one is correct, here’s what you can do:

• First, check through all the meanings and find the one that makes most sense in the context where you found the word. (Very often, many of the different meanings are similar and this should be enough to give you a good idea what the word means.)
• Second, if you really want to make sure, think what the word is in your own language and look it up in a bilingual dictionary. If one of the English translations is the original word you looked up, then you can be satisfied that you have found the right meaning. 

Finding the right spelling

Another problem you may have is when you want to check your spelling but you can’t find the word you’re looking for. What can you do?

• If you are sure of the first few letters, just look down the page until you find the right spelling. (Again, it is helpful to check the meaning is the one you expect.)
• If you are not sure of the first few letters, try some other possibilities. You know for example that some words that start with an -n sound have k as their first letter; e.g. knife, knight. So if you can't find the word under N, try looking in the K pages.
• If you still can’t find the word, think what it is in your language and look it up in your bilingual dictionary. 

Finding the right English translation of a word in your language

When you look up a word in your own language in a bilingual dictionary, you will probably find that there is more than one English translation. If you are not sure which to use, you could try a back translation. This means that you look up the English translations one by one in a monolingual dictionary. If a word has a definition that matches the word in your language, you are safe to use it.

Knowing when to use the dictionary

If you look up every new word you see or hear, you will spend your whole day with the dictionary in your hand. That’s no good! You have to be clever and choose the right words to check and the right time to do it. Try to follow the advice below and you will become a much more efficient language learner:

• When you find a new word while reading, finish the sentence (better: the paragraph). If you haven’t guessed the meaning and it still seems important, then you can look it up. To avoid interrupting your reading for too long, you should find its meaning in your own language using a bilingual dictionary.
• When you hear a new word in class (or the teacher has written it on the board), wait and continue listening. What the teacher says next may help you to understand the word. If you look in your dictionary, you will not hear what comes next, and this will make understanding the lesson more and more difficult.
• If you think the word is very important, you could copy it from the board or write how you think it is spelled. Then later you could ask the teacher or another student what it means.