Ok, I watched this video 3 times (one time with english subtitles, then one time with russian, and againthen one time with english subtitles again).

When you're talking about things in the order they occurred, use connecting words like "then" to indicate that.

It's a really interesting video about pulleys and how they work👍

AThe author of the video really likes snatch blocks.

He tellalks about how thisese pulleys can help [???]

"Tell about" isn't used very often. "Tell about" usually means there is specific, crucial information being conveyed (e.g. "He told me about the party, so I knew it was happening."), while "talk about" means that more general information is being conveyed (e.g. "He talked to me about the party, so I knew it was Disney themed.")

Also, this isn't a complete sentence. Using "help" at the end of the sentence like this requires context: it should be obvious what issue the pulleys are helping to resolve.

Snatch blocks redirecting force in the ropes and with ropes we get a mechanical advantage

I don't really understand what you're trying to say here.

However, this man saytalks about some interesting situations, when snatch block helps [???]

Again, not a complete sentence.

Ok, I watched this video 3 times (one time with eEnglish subtitles, one time with rRussian andsubtitles and then again with eEnglish subtitles).

It's not technically wrong, but I probably wouldn't start this sentence with Ok.

It's a really interesting video about pulleys and how they work. 👍

AuthThe creator of the video really likes snatch blocks.

Generally author is only for writing.

He tell aboutshowed how thiso use pulleys can help.

Snatch block redirecting force in ropes and with ropes we get mechanical advantageYou can use ropes and pulleys for leverage and use the forces to redirect the snatch blocks.

I'm not quite sure what you're trying to say here, so this correction may not be right.

However, this man saye also talked about some interesting situations, whenre snatch block helpss are useful.