Similar-sounding words often have very different meanings!   Think of the likes of   two/to/too         accept/except          there/their/they’re

Some commonly confused homonyms are:

complement  (the flavour of the basil complements the tomato)  *See below for the use of complementary.

compliments (I get all the compliments) – think about it as ‘I’ get all the compliments

dependant  someone who depends on somebody for support (noun)   

dependent (you are dependent on me to pick you up from school even though you are a very independent child)

it’s (only ever used for it is or it has) It’s a lovely day

its (plural or ownership – the badger wagged its tail – never has a possessive apostrophe)

licence  formal permission from an authority to do something

license  to give permission or licence to do (a club is licensed to serve alcohol)

practice (ice is a noun – a doctor’s practice)

practise (practise your spelling)

principal (is my pal)

principle

stationery (e in envelopes) stationary – the car was stationary

Similar sounding words

What about Affect vs. Effect? 

Affect   To have an influence on or cause a change inInflation affects the buying power of the dollar/To act on the emotions of; touch or move/To attack or infect, as a disease: Rheumatic fever can affect the heart.

Effect  Something brought about by a cause or agent; a result/The power to produce an outcome or achieve a result; influence: The drug had an immediate effect on the pain. The government’s action had no effect on the trade imbalance/ A scientific law, hypothesis, or phenomenon: the photovoltaic effect. |Advantage; avail: used her words to great effect in influencing the jury.

Grammar Rules for Affect and Effect

If you are talking about a result, then use the word “effect.”

  • Example: What effect did the loss have on the team?

Use the word “effect” if one of these words is used immediately before the word: into, on, take, the, any, an, or and.

  • Example: The prescribed medication had an effect on the patient’s symptoms.
  • Example: In analyzing a situation, it is important to take the concepts of cause and effect into consideration.

To describe something that was caused or brought about, the right word to use is effect.

  • Example: The new manager effected some positive changes in the office. (This means that the new manager caused some positive changes to take place in the office.)

Affect can be used as a noun to describe facial expression.

  • Example: The young man with schizophrenia had a flat affect.
  • Example: The woman took the news of her husband’s sudden death with little affect.

 Affect can also be used as a verb. Use it when trying to describe influencing someone or something rather than causing it.

  • Example: How does the crime rate affect hiring levels by local police forces?
  • Example: The weather conditions will affect the number of people who come to the county fair this year.

Lose and Loose. If you lose your passport, you’ll need to advise the Embassy. The passport fell out when the strap came loose.

Quiet and quite. Please be quiet, the baby is asleep.  The baby is quite a good sleeper

 Your and You’re.  Your phone is ringing.  You’re (You are) taking your time to pick up your phone.

* Complementary and Complimentary (from the Oxford Dictionary)

Unsurprisingly, the adjectives relating to compliment and complement also cause confusion. Complimentary has two meanings. It can mean ‘expressing admiration or praise’:

  • I have received many complimentary remarks from members of the audience.
  • The vast majority of our patients are extremely complimentary about the care they have received.

It can also mean ‘given or supplied free of charge’, as in the following sentences:

  • Complimentary light refreshments will be available.
  • Most theatres offer complimentary tickets if you review their show for the paper.
  • We offer a complimentary shuttle service to the airport and historic old town.
  • Guestrooms offer complimentary bottled water and fresh fruit daily.

It’s common to see complementary used in these sorts of contexts, but this is a mistake. For instance, both the following examples are using the wrong spelling:

X There will be an opportunity to meet the artists and have a complementary glass of wine.
X The winner will receive two complementary tickets to a performance of their choice.

Complementary should instead be used to describe things that combine in such a way as to enhance or emphasize each other’s good qualities:

  • They had different but complementary skills.
  • We view this proposal as complementary to existing policing services.
  • Interior design and architecture are two complementary professions.

Source: http://blog.oxforddictionaries.com/2011/04/compliment-or-complement/