I learned about "what it" from the below videovideo below on YouTube. I learned about "what it" from the video below on YouTube.

It's always "the <thing> <direction>". For example "the sign above", "the link below"

I learned about the phrase "what it" from the below video on YouTube. I learned about the phrase "what it" from the below video on YouTube.

https://youtu.be/9t0zGOLfTuE?si=JgMYTwj3EZW9ifU7 https://youtu.be/9t0zGOLfTuE

I'm sad I can't post this in your native language. This post is not easy to understand, but I have critique of the video you were studying. I mean this in the kindest way possible. I think you should be careful listening to this video for learning because it has many mistakes. (1) The audio dialogue of this video is almost completely unintelligible and doesn't match the English words that are shown on screen. (2) The video does not practice good English, even in the first example they provide. "I don't understand what it feels like." The direct object of the sentence is verb form of the noun "feeling" (aka an emotion). The feeling (emotion) is the thing you do or don't understand in this context. The direct object is more important for understanding the meaning of the sentence than the word combination "what it." "What it" is a decorator that is used to distinguish nature of the feeling (emotion). In this context "what it" allows the verb to describe an abstract emotion to feel like love, pain, and sadness. If you change "it" to "he," then the verb to feel describes the physical sensation of touching a person or animal, like what a dog's fur feels like. "I don't understand what love feels like" has a closer meaning to "I don't understand what it feels like." The direct object of "to understand," which is your main verb, is the action of feeling, and the descriptor of what type of emotion you are feeling is love. "I don't understand what he feels like." is not good grammar. A native speaker can understand you, but it is implying that you don't have the ability to understand the physical sensation when you reach out with your hand and touch whoever "he" is. Most likely what the video is trying to express is: "I don't understand what he is feeling." By adding "is" here, the direct object is "is feeling," aka the current emotional state of the other person. "is" is a helping word for the action of "feeling" and establishes that the emotion being felt is in the current moment. The words "What he" describe who is in the current state of feeling an emotion. That is the person that "he" refers to.

Examples from the video Examples from the video

Examples from the video Examples from the video

Multiple examples are presented here, so "examples" should be plural.

I don't understand what it feels like to be a powerfule mage. I don't understand what it feels like to be a powerful mage.

I don't understand what it feels like to be a powerfule mage. I don't understand what it feels like to be a powerful mage.

I don't understand what it feels like to be a powerfule mage. I don't understand what it feels like to be a powerful mage.

If that's what it takes to eliminate the demons... If that's what it takes to eliminate the demons...

This is not a complete sentence, so you're correct in choosing not to add a period at the end. When you're quoting a sentence fragment, an ellipsis ("...") may be necessary to indicate that the rest of the sentence is omitted.

I know what it takes to play baseball. I know what it takes to play baseball.

I know what it takes to play baseball. I know what it takes to play baseball.

I know what it takes to play baseball. I know what it takes to play baseball.

I know what it takes to play baseball. I know what it takes to play baseball.