October 2026 - Spelling & Commonly Confused Words Study Guide

The pairs that appear most

Confusions worth knowing for clinical writing

• Lie / lay — you lie down yourself; you lay something down. The past tense of lie is lay, which is what makes the pair so difficult.
• Fewer / less — fewer for things you can count (fewer patients), less for quantities you cannot (less fluid).
• Its / it's — possessive against "it is". See the apostrophe topic.
• Complement / compliment — one completes, the other praises.
• Discreet / discrete — tactful, against separate and distinct.

Spelling rules that hold often enough to use

• i before e except after c — believe, receive. Real exceptions exist: weird, seize, height, their.
• Doubling — with a short vowel before a single final consonant, double it before adding a vowel ending: stop → stopping, refer → referred.
• Silent e — drop it before a vowel ending, keep it before a consonant ending: hope → hoping, but hope → hopeful.
• y to i — change y to i before most endings: carry → carried, happy → happiness.

Applying a substitution test

Terms to know

Homophone

A word that sounds like another but is spelled differently and means something else.

Affect

Usually a verb: to influence.

Effect

Usually a noun: a result.

Than

Used for comparison.

Then

Used for time or sequence.

Fewer

Used for things that can be counted.

Less

Used for quantities that cannot be counted individually.

What the TEAS asks most

The same core ideas appear in different wording. If you can answer these without stopping to think, you have what this section requires.

Key points

• Affect is the action; effect is the end result.
• Than compares; then is about time.
• Fewer for what you can count, less for what you cannot.
• You lie down; you lay something down.
• Test each pair by substitution rather than trying to recall a rule.