Thing
Matter, Action
noun
The kanji and the word are exactly the same. That means they share meanings as well. Additionally on top of thing there are the meanings matter and action as well. Like the kanji, this word has to do with action things... things that you do, for example, rather than physical things.
こと
Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word:
It's hard to start a mnemonic with the word "thing" or "action," so let's continue off the kanji mnemonic where you've put a cross in the mouth of a wolverine. Why did you do it? You knew that feisty wolverine was going to eat your coat (こと).
スモモさんが、ピンク色のいしょうをきる事が多いのはなぜですか？
Why do you think Ms. Sumomo wears so many pink clothes?
後はいが言っている事がいつもよく分からなくてこまっています。
I often have trouble understanding what my junior colleague is saying.
すまないが、ちょっと今はする事がたくさんあって、忙しいんだ。
I’m sorry but I’ve been busy recently because I have a lot of things to do.