Your computer can check the spelling in your fiction for you, but it won’t pick up your typos and it won’t pick up wrong gender adjectives, such as blond for blonde, where the owner of the hair is female.
But wrong gender adjectives are the least of your worries. The computer can’t pick up homonyms. What’s a homonym?
A homonym is a word pronounced the same way as another, but differing in meaning, whether spelled the same way or not. For example:
The site of thee blond girl standing sunder the bow of a tree was to much four me. She was sew beautiful. I wood have liked to stroke her hare. She was standing on the sight of a demolished building. I boughed two her butt she did knot respond oar acknowledge my presents inn any weigh. Perhaps she wood right about me in her dairy at knight but that hat not bean my gaol.
Sure, I’m pushing it to make a point, but you get my drift.
How many mistakes do you think the computer picked up?
There are actually 26 spelling mistakes: 21 homonyms (in Italics), 1 wrong gender adjective (in Bold Italic) and 4 typing errors (in Bold).
There is no substitute for a dictionary. Just a small one will do.