Describing people – character

Intellectual ability
– Ability: intelligent bright clever smart shrewd able gifted talented brainy (colloquial)
– Lacking ability: stupid foolish half-witted simple silly brainless daft dumb dim (the last four are predominantly colloquial words)
– Clever, in a negative way, using brains to trick or deceive: cunning crafty sly

Attitudes towards life
– Looking on either the bright or the black side of things: optimistic pessimistic
– Outward-looking or inward-looking (i.e. to the world around one or to one’s own inner world): extroverted introverted
– Calm or not calm with regard to attitude to life: relaxed tense
– Practical, not dreamy in approach to life: sensible down-to-earth
– Feeling things very intensely: sensitive

Attitudes towards other people
– Enjoying others’ company: sociable gregarious
– Disagreeing with others: quarrelsome argumentative
– Taking pleasure in others’ pain: cruel sadistic
– Relaxed in attitude to self and others: easy-going even-tempered
– Not polite to others: impolite rude ill-mannered discourteous
– Telling the truth to others: honest trustworthy reliable sincere
– Unhappy if others have what one does not have oneself: jealous envious

One person’s meat is another person’s poison
– Some characteristics can be either positive or negative depending on your point of view. The words in the right-hand column mean roughly the same as the words in the left-hand column except that they have negative rather than positive connotations.