A ‣ Adjectives to describe people’s personality or behaviour 
word | meaning | example |
impetuous | acts on a sudden idea without thinking first (often negative) | She’s so impetuous; I wish she would consider things before acting. |
impulsive | similar to impetuous, but can be used in a more positive way | His impulsive generosity led him to give money to anyone who asked for help. |
effusive | gives exaggerated expression of pleasure, praise or gratitude | She always gives me such an effusive welcome when I visit her. |
excitable | easily excited by things | He’s a very excitable child; he needs to calm down. |
pushy | always selfishly promoting your own position or interests; informal | She’s so pushy; it’s typical of her to demand a pay rise for herself and not care about the rest of us. |
self-conscious | nervous or uncomfortable because you know what people think about you or your actions | Freddie seemed self-conscious and uncomfortable when he had to make the announcement at the party. |
well-balanced | calm and reasonable and showing good judgement | The teacher said Maddy was a well-balanced child who got on well at school. |
taciturn /ˈtæsɪtɜːn/ | reserved or says very little (generally negative) | He was a bit taciturn when I first met him. He hardly said a word. |
B ‣ Sociability 
Chloe’s such an introvert. Her brother Mark is so outgoing and is such an extrovert. Strange, isn’t it? [inward-looking and quiet] [energetic and friendly, finds it easy to be with others] [outward-looking, energetic and sociable]
Mr Rogers is such a diffident man. He seems to have quite low self-esteem. [lacks confidence] [has a low opinion of himself]
English people are traditionally thought of as rather reserved. [not immediately sociable]
Eva tends to be rather aloof. I don’t know if she’s just shy. [unfriendly and not sociable]
My aunt Annie can be very haughty and disdainful at times, but she’s lovely really. [unfriendly and thinks herself better than others] [does not believe others deserve respect]
I’ve always found Professor Mactoft very unapproachable, but his colleague Dr O’Daly is very approachable. [not easy to be sociable with or start a conversation with] [the opposite]
Natasha is very conceited and self-important, but Rachel is such a modest person. [thinks herself wonderful] [has an exaggerated sense of her importance] [prefers not to exaggerate her own qualities]
Joe is always so polite and respectful. I wish he would be more informal and just treat me as his equal. [treating someone well and politely, often with admiration]
C ‣ Character traits 
Arjen is a somewhat naive person; he thinks love can solve all the world’s problems. [/naɪˈiːv/ willing to believe simple things, perhaps because of inexperience]
Telephone salespeople often take advantage of gullible people. [easily deceived]
My father was a very conscientious man; he never took time off work unless he was really sick. [/ˌkɒntʃiˈentʃəs/ always took his work very seriously]
She’s a restless individual. I don’t think she’ll ever settle down in a job. [not satisfied with what she is doing now and wanting something new]
You are so obstinate and pig-headed! Why don’t you listen when people give you advice? [unwilling to change, despite persuasion] [similar to obstinate but stronger; informal]