Theory:

Homophones are pairs of words that sound the same but have different meanings and different spellings.
Example:
1. steal/steel:
Someone who decides to steal a bicycle has committed a crime, but some parts are made of steel.
2. tail/tale:
My dog was crazily chasing his tail while I read a fairy tale to my kids.
3. weather/whether:
I don't know whether to wear  boots or not. The weather looks unpredictable today.