Here are a few pairs of words that are easily confused.
(a) plane and plain
plane (adj) = a flat or level surface
A plane surface is never curved.
plane (n) = aeroplane
James loves travelling by plane
plain (adj) = simple / easy to understand
Can you explain this in plain English, please?
She was wearing a plain dress at the party.
plain (n) = a vast area of flat land
The plains of central China take your breath away.
(b) popular, famous and folk
popular (adj) = loved and admired by many people
Helen is a popular girl. She's got many friends.
famous (adj) = loved and admired by many people all over the world
Tom Cruise is a famous actor.
folk (adj) = of the common people in a country
John enjoys folk dance and folk music.
(c) sympathy and affection
sympathy (n) = a feeling of pity
She has no sympathy with her mother's misfortunes.
affection (n) = love and tenderness
Nothing can match a mother's affection for her children.
(d) refuse and deny
refuse = say no
Mary kindly refused my invitation to dinner.
deny = say that something is not true
He denied having committed the crime
(e) scratch and scrape
scratch (v) = make lines on a surface, usually with something sharp
The cat scratched me.
scrape (v) = remove by pushing something rough along a surface
She had to scrape the sticky saucepan.
I tried to scrape some of the mud off my shoes.