I knew what you want to say but i regarded you about the red word you had used .
In positive sentence , you must use "something" instead of "anything".....that means.....Instead of using "I can do anything",you must say that " I can do something".
About "IT" word that you typed , i understood that it's capitalized but i want to say a difference , "IT" word is abbreviation , it stands for what i'm sure you know ....
We can discuss more about many topics , i'm glad to discuss with U
"Difference in form always implies some difference in meaning". I do not question the use of "something" and "anything" in simple positive/negative statement, but sometimes when they can be used interchangeably, the meanings may matter.
"Something" can be used to refer to the particular idea while "anything" implies more generic idea. Try these:
There's something I need to tell you. RIGHT
There's anything I need to tell you. WRONG
Not only grammatically, but the second sentence is meaningless.
Dad - I want you to tidy your room.
Son - Anything you say, Dad. RIGHT - not really a negative statement, right?
I want something sweet. A strawberry? No. A soda? No. Some ice cream? No. I just can't make up my mind.
vs.
I want anything sweet. It doesn't matter what it is, as long as it's sweet, I'll take it!
Different meanings.
Would you like something else?
Invites a positive respone.
Would you like anything else?
Invites a negative response.
---------------------
So, please think about the reason why I used the phrase "I can do ANYTHING". Have you heard anyone saying "I can do something" without a second phrase attached to it? I guess not.
And, please do not use the word "must". Language is used to communicate and express views, so everyone can use it the way they see fit, as long as they can express what they think (eventhough somebody may not understand). It will discourage others to try using English here knowing that they have some problems speaking it fluently.
Not to mention that you are nobody to tell me what I "MUST" do