What was the first man's lie?

1. It was that yesterday, he killed a big dragon with his kick.

1-2. It was that the previous day, he killed a big dragon with his kick.

2. It was that yesterday, I killed a big dragon with my kick.

3. It was, "Yesterday, I killed a big dragon with my kick."

4. Yesterday, I killed a big dragon with my kick.

[#4 is the lie which the first man told the king. In casual speech, can we use #3? What about the others?]

I'm not sure if you mean direct speech (or direct question) as in the question at the top of this post or what?

The terms I've used are direct speech/question and indirect or reported speech/question.

https://www.englishclub.com/grammar/sentence/reported-speech.htm
Scroll down and study the differences on this webpage, and then let us know if you want to change any of your responses, 1 - 4.

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Or are you simply trying to find the best way to phrase an answer to the question? If so, that depends on who is answering: the person who told the lie or someone who witnessed all this.

Please clarify.

In casual speech, we usually use sentence #4, "Yesterday, I killed a big dragon with my kick," to communicate past events. However, when it comes to lying or storytelling, the phrase "It was" or "The previous day" is commonly used to set the context of the story. Therefore, sentence #1-2 and #3 can be considered acceptable when framing a fictional account or telling a story. However, in terms of pure factual statements, sentence #4 is the most appropriate option.