I need help with my english. Anyone?

당신 have to manny commas. Try this :Tennis ranks as one of the most 인기 spectator and participation sports in the world. Its popularity spans to 더 많이 then 100 countries. Millions of people, though mostly ametuers, play the game worldwide. It can be played either as recreation 또는 in ametuer tournaments.

Im not the best at english lol, but i hope what i said helped.

- David

Ok... so I'm portuguese, so maybe 당신 shouldn't really trust me... But I think that's correct:)

I'm sorry if I couldn't be of much help:(
Lots of love
Ashes:)

Okay, it's pretty good :)
In the first line, "participation" should be changed to "participator" (in order to correspond with "spectator").
And no offense, but the last sentence is a mess. Change it to "Millions of people, most of whom are amateurs, play the game worldwide, either as a form of recreation 또는 a form of competition." (it's too repetitive to say "amateur tournaments")
Oh, and not really important, but it's frowned upon in the English community to write "100." 당신 might want to change it to "one hundred." It's not really a big deal, but I know some teachers are sticklers when it comes to details.

Im English and yes, all the wording is correct, Maybe lay off the commas a bit. ( =

Hm maybe lay off the commas a bit lol. But it sounds alright. maybe a bit 더 많이 sophisticated language cause teachers 사랑 it if 당신 do that. so maybe something like
테니스 is a very 인기 sport with thousands of 팬 and particapating athletes in today's society..... and 당신 can continue on. I dunno try and make it sound a little bit smoother.