Words that don’t sound alike but confuse us anyway

Lie, Lay

Lie is a verb meaning to recline or rest on a surface. Its principal parts are lie, lay, lain.
Example: I lie down on the couch and watch TV.

Lay is a verb meaning to put or place. Its principal parts are lay, laid.
Examples:
I lay the the keys on the table when I get home.
Chickens lay eggs.

Set, Sit

Set is a verb meaning to put or to place. Its principal parts are set, set, set.
Example: I set plates and utensils on the table before dinner.

Sit is an intransitive verb meaning to be seated. Its principal parts are sit, sat, sat.
Example: The students sit in their assigned desks for math class.

Who, Which, That

Use who to refer to people, which and that to refer to things. In many instances, like in the example below, that isn’t even needed.

Examples:
I just saw a woman who was wearing my same coat.
I dread going to math class, which is my hardest class.
Where is the book that I was reading?