'Some' means an unspecified amount or number; 'sum' is the total of added numbers or an amount of money.
Determiner/pronoun/adverb. An unspecified amount or number of. Certain people or things. Also informally: to some degree (that was some achievement).
Could I have some water, please?
Some of the delegates arrived late to the opening session.
We need some extra time to finalise the budget.
Noun/verb. The total result of adding numbers together. An amount of money. To summarise (to sum up).
The sum of all expenses exceeded the annual budget by fifteen percent.
She invested a significant sum in upgrading the company servers.
To sum up, we need to reduce costs and increase revenue simultaneously.
Common mistake
"The some of all the numbers" (correct: sum). Or "To some up the meeting" when meaning summarise (correct: sum up). The phrase 'in sum' (to summarise) is often written 'in some'.
Trick to remember it
'Some' ends in OME like 'home' and 'come' — comfortable, familiar, indefinite. 'Sum' ends in UM like 'number' and 'drum' — precise, mathematical, countable.
Quick rule
Is it an unspecified amount or 'certain ones'? 'Some'. Is it the total, a money amount, or to summarise? 'Sum'.
Did you know?
'Sum' and 'summit' share the Latin root 'summa' (the highest amount, the top). A summit is literally the highest point — the sum of all elevation. 'Summary' and 'summarise' come from the same root. Interestingly, 'summer' does NOT come from 'sum' — it comes from Old English 'sumor' with an entirely different etymology. The similarity is pure coincidence, which surprises most people who assume summer is somehow the 'sum' of the year.
Exercise 1 · Pick the right one
Could you _____ up the key points from the meeting for those who could not attend?
Exercise 2 · Pick the right one
We still have _____ budget remaining — let us allocate it to the marketing campaign.
Exercise 3 · Form the word
Is it an unspecified amount or 'certain ones'? 'Some'. Is it the total, a money amount, or to summarise? 'Sum'.
"The some of all the numbers" (correct: sum). Or "To some up the meeting" when meaning summarise (correct: sum up). The phrase 'in sum' (to summarise) is often written 'in some'.
'Some' ends in OME like 'home' and 'come' — comfortable, familiar, indefinite. 'Sum' ends in UM like 'number' and 'drum' — precise, mathematical, countable.
Bryan López
Founder of SpeakUP Academy