Collocations
panels show you which words are typically used together. For example, we might talk about ‘glorious weather’ or ‘lovely weather’, but if the noun we want to use is ‘experience’, we would be more likely to talk about a ‘memorable experience’ or a ‘rewarding experience’. The numbers refer to the particular meaning within the main entry. A knowledge of collocations will help you to sound natural and fluent when you are speaking and writing in English. 
Usage notes
give tips on avoiding common learner errors in grammar, vocabulary, and pronunciation. These include uncountable nouns that learners often mistakenly use as if they were countable, typical preposition errors, and commonly confused words. Browse the dictionary for these invaluable notes and find out how to avoid all the most frequent mistakes in English. 
Prefixes and suffixes
are parts of words that help to give them their specific meaning. For example, words that start with the prefix poly-
usually have ‘many’ as part of their meaning, and words that end in -ly
are often adverbs that indicate how something is done. Knowing a range of prefixes and suffixes will help you to work out the meanings of words by yourself, without always having to look the word up. 
Word histories
tell you where certain words come from and how they have changed in meaning over the years. For example, did you know that the word ‘slogan’ comes from a Gaelic word meaning ‘war cry’? Or that the word ‘hippopotamus’ comes from the Greek for ‘river horse’? Finding out the history of a word can be fascinating and sometimes surprising, and the images and ideas formed in our minds can help us to remember the word we have learnt about. 
Word classes
ADJ
An adjective can be in the comparative or the superlative form.
ADV
An adverb can be in the comparative or the superlative form.
AUX
An auxiliary verb is used with another verb to add particular meanings to that verb, for example, to form the continuous aspect or the passive voice, or to form negatives and interrogatives. The verbs be, do, get, and have have some senses in which they are auxiliary verbs.
COLOUR
A colour word refers to a colour. It is like an adjective, e.g. The sky was blue, and also like a noun, e.g. She was dressed in red .
COMB
A combining form is a word which is joined with another word, usually with a hyphen, to form compounds.
CONJ
A conjunction usually links elements of the same grammatical type, such as two words or two clauses.
CONVENTION
A convention is a word or a fixed phrase which is used in conversation, for example when greeting someone, apologizing, or replying.
DET
A determiner is a word that is used at the beginning of a noun group, e.g. a tray, more time, some books, this amount . It can also be used to say who or what something belongs or relates to, e.g. his face, my flat, or to begin a question, e.g. Whose car were they in?
EXCLAM
An exclamation is a word or phrase which is spoken suddenly, loudly, or emphatically in order to express a strong emotion such as shock or anger. Exclamations are often followed by exclamation marks.
FRACTION
A fraction is used in numbers, e.g. three and a half, two and two thirds; before of and a noun group, e.g. half of the money, a third of the biscuits, three eighths of the pie; after in or into , e.g. in half, into thirds . A fraction is also used like a count noun, e.g. two halves, the first quarter of the year .
MODAL
A modal is used before the infinitive form of a verb, e.g. You may go . In questions, it comes before the subject, e.g. Must you speak? In negatives, it comes before the negative word, e.g. They would not like this . It does not inflect, for example, it does not take an -s in the third person singular, e.g. She can swim .
N-COUNT
A count noun has a plural form, usually made by adding -s . When it is singular, it usually has a determiner in front of it, such as the, her, or such .
N-PLURAL
A plural noun is always plural, and is used with plural verbs. If a pronoun is used to stand for the noun, it is a plural pronoun such as they or them , e.g. These clothes are ready to wear . Plural nouns which end in -s usually lose the -s when they come in front of another noun, e.g. trousers, trouser pocket. If they refer to a single object which has two main parts, such as jeans and glasses , the expression a pair of is sometimes used, e.g. a pair of jeans . This is shown as N-PLURAL [oft a pair of N ].
N-PROPER
A proper noun refers to one person, place, thing, or institution, and begins with a capital letter. Many proper nouns are used without a determiner, e.g. … higher education in America … Father Christmas ; some must be used with the .
N-PROPER-PLURAL
A plural proper noun is a proper noun which is always used in the plural with a plural verb.
N-SING
A singular noun is always singular, and needs a determiner.
N-TITLE
A title noun is used to refer to someone who has a particular role or position. Titles come before the name of the person and begin with a capital letter.
N-UNCOUNT
An uncount noun refers to things that are not normally counted or considered to be individual items. Uncount nouns do not have a plural form, and are used with a singular verb. They do not need determiners.
N-VAR
A variable noun typically combines the behaviour of both count and uncount nouns in the same sense. The singular form occurs freely both with and without determiners. Variable nouns also have a plural form, usually made by adding -s . Some variable nouns when used like uncount nouns refer to abstract things like hardship and injustice , and when used like count nouns refer to individual examples or instances of that thing, e.g. He is not afraid to protest against injustice. … It is never too late to correct an injustice . Others refer to objects which can be mentioned either individually or generally, like potato and salad : you can talk about a potato, potatoes , or potato .