For some writers, their main spelling problem is similar-sounding words, for example, principle and principal or affect and effect. These problems cannot be flagged by software spell-checking functions.

Here is a list of these commonly confused homophones (different spelling, same or very similar pronunciation), with examples of their correct use.

accept, except
The construction form accepted the offer to build the bridge.
Everything has been finished except for the paint job.

advice, advise
The construction firm ignored the engineer's advice.
The engineer advised the firm to use single-suspension walkways.

affect, effect
The effect of the increased oil prices has been devastating on our economy.
The increased oil prices have affected our economy drastically.

cite, site, sight
The consulting engineer cited a paragraph from the building code.
At the construction site, the workers carefully erected the scaffolding.
The collapse of the walkways was a terrible sight.

complement, compliment
The programmer has received many compliments on her new system.
The colors that have been selected for the room do not complement each other.

counsel, council, consul
She was appointed consul to the embassy in Beirut.
There was lengthy debate on the tax proposal at city council last night.
He counselled her to get a degree in technical communication.

its, it's
It's time to go home; it's getting late.
The car has lost one of its headlights.

lose, loose
Your car loses power when it is out of tune.
I have some loose change in my pocket.
Don't let Mamie get loose!

personal, personnel
They plan to take out a personal loan to build the deck.
Send your application to the personnel office.
The CEO wants to have a personal chat with all this company's personnel.

principal, principle
The principal component of the solar panel is the collector.
Explain to me the principle of convection.

stationary, stationery
Use company stationery for company business purposes only.
The derrick may not remain stationary during the gale-force winds.

than, then
My utility bill was higher this month than it was last month.
The hurricane reached the Texas coast; then it plunged right into the heart of Houston.

their, there, they're
Their calculus course is much harder than ours.
Over there on the table is your calculus book.
They're not taking calculus this semester.

to, too, two
Are they going to pave the street today?
It is still too rainy to pave the street.
Two hours ago, the sky was clear.

whose, who's
Whose technical writing book is this?
There is the woman whose technical report won top honors.
Do you know who's in charge around here?
He's a man who's not afraid of criticism.

your, you're
Your technical writing book is on the table.
You're going to have review Part 1 before writing that report.