parenthesis

Everyday

1. (punctuation) A word, phrase or sentence put into another sentence as extra information, marked by brackets, commas or dashes. tree →
2. (US) One of the round brackets ( ). tree →
3. (maths) Round brackets that show which part of a calculation to do first. tree →

In the lessons

In grammar lessons (UK Key Stage 2), pupils learn parenthesis: extra information marked by brackets, dashes or commas, as in «My dog (who is very old) sleeps a lot». In maths, operations inside parentheses are done first (BIDMAS, BODMAS, PEMDAS). Phrases: «in parentheses», «use parenthesis», «brackets for parenthesis».

Examples

• My cat, who is very lazy, sleeps all day — this is parenthesis with commas. tree →
• Put extra information in parentheses (like this). tree →
• In maths, work out the parentheses first: (3 + 4) × 2 = 14. tree →
• Use dashes for parenthesis — they make it stand out. tree →
• The teacher asked us to add a parenthesis to our sentence. tree →
• In the US, ( ) are called parentheses; in the UK they are usually «brackets». tree →

Note

Plural «parentheses» (-is → -es, like crisis/crises). Adjective «parenthetical». Maths: (2 + 3) × 4 = 20 but 2 + 3 × 4 = 14 — brackets change the answer. Trap: in UK school grammar «parenthesis» means the extra phrase itself; in US use it often means the bracket marks.