How do you know what is the current market situation eg correction, crash, bullish?

Adding to what Jovan has said, if you look at different time frame also it tells you a different story. Last year March 2020, stock market was like, "Wah siao liao! Crash! Armageddon!" But if you look at the whole of 2020 extending into 2021, it was more like, "Wah win! Going to the moon!"

So perspective and time frames matter too.

The harsh truth is that you can never be certain. Uncertainty is the only certainty in the markets.

I know this is not the answer you were hoping for but that’s the only honest answer I can share. If you can know for certainty, then it’s so easy isn’t it? Quit your job, sell everything and pump into whatever market u are bullish in, leverage it x999999... you will be a multi-millionaire in a few months

What makes the market work is uncertainty itself, thus it is more important to develop/find, understand and stick to a strategy that gives you an edge over the market over the long period of time.