This is the first of an occasional 'study skills' type post. I've noticed, both as a librarian and in day to day work that many people struggle with these type of skills, and spending a bit of time trying to get these right can really make a difference both in professional work and personal communication.
Today, getting the right word when words sound similar but mean slightly different things:
Enquire / Inquire
Actually both can be used, but enquire is commonly used for an informal 'to ask', and inquire for a more formal 'inquiry'.
Accept / Except
You may accept a gift, or accept or agree with a suggestion, but except is to put something aside or refuse it, for example, "I'll take all the fruit except the oranges".
Affect / Effect
Affect is to realise or fulfil something, eg. the oven temperature affects the baking of a cake. An effect is the consequence of something, eg. the low oven temperature had a poor effect on my cake.
Lose / Loose
Lose is to misplace something, eg. you lose you keys. Something is loose when it is not 'fixed' or set, eg. the screws are loose.
Bored / Board
Might seem an obvious one, but bored is what you used to be in Maths, ie. not interested. Board is a rigid piece of card, or a committee.
Biannual / Biennial
I get confused myseldf with this one: biannual means happening twice a year, and biennial is every two years.
Compliment / Complement
Compliment means praise or saying something nice about someone, eg. you give someone a compliment. Complement means in addition to something, or a complement slip in formal letters.
Discreet / Discrete
Discreet means respectful, low key about someone or something eg. "be discreet about that issue". Discrete means separate or distinct, eg. the documents are in discrete packages.
Ensure is when you try and 'make sure' of something, eg. Ensure you pack your swimming costume.
Insure is taking out insurance on the car. Enquire is Inquire is
Disinterested / Uninterested Disinterested is when you don't benefit from a situation, eg. A lawyer is disinterested in the outcome of a will. Uninterested is... just plain bored (see above).