principle – principal
A principle is a rule or law:
In principle, the two types are …
Principal means the main or most important:
the principal cause …
the principal investigator …
A simple way to remember the difference between principle and principal is that principle ends in the same letters as rule, and the ending of principal contains the same letter as main.
effect – affect
Effect means result:
The effect of … was immediate.
… proved to be very effective
Affect means to influence, especially negatively:
Normal life in parts of Africa is greatly affected by HIV and AIDS.
discrete – discreet
Discrete means separate or distinct:
The process consists of a number of discrete stages.
Discreet means tactful and confidential:
The reviewers’ comments are always discreet.
complementary – complimentary
Complementary means to add to or complete:
A simple way to remember this is that complementary contains the same letters as complete.
Complimentary means with praise:
a complimentary review
precede – proceed
Precede means to go or be before:
The discovery of … preceded … by fifty years.
Proceed means to go forward:
The grant meant that we could proceed with the research.
lead – led
Lead is the present tense of the verb to lead:
Poor sanitation often leads to health problems.
Led is the past tense:
The discovery of penicillin led to many improvements in health care.
Immunization campaigns have led to the eradication of many diseases.
Lead is a metal:
Lead poisoning can result from drinking contaminated water.
choose – chose
Choose is the present tense of the verb to choose:
Students choose three options.
Chose is the past tense:
She chose the University of London because of its cosmopolitan atmosphere.
lose – loose
Lose means to lose something
We should not lose sight of the fact that …
Loose means lax:
A loosely worded argument
advise – advice
Advise is a verb and means to give advice:
Most doctors advise their patients to stop smoking.
Advice is a noun:
My supervisor’s advice was very helpful.