On the way to underground today, => What is "underground"? An underground structure? It is not a term used this way. I heard that one father talked to his kid when passing a yard, => "I heard that" means you heard it indirectly from someone or the media. => If you heard it directly, you would say "I heard a father talking to his kid.." he said:"look at your face,just like dirty ass,what's the hell thing you want to do,go begging?" => "dirty ass" sounds strange to me. => "the hell thing" is strange too. "What the hell do you want to do" would be better. what I think about immediately is that it's his kid? => A better sentence would be: I think immediately, "Is that (really) his own kid?" * Punctuation and capitalization rules are not being followed, making it hard to read.

Not too wrong. I'll re-write it and then explain: "On my way to the underground today, I heard a father talking to his kid whilst they/I were/was passing a yard. He said "look at your face, it's just like a dirty as.. What the hell do you want to do, go begging?" My first thought is 'is that his kid'? Your meaning is pretty much clear, just be careful of swapping tenses. What you mean to say, I think, is that you were heading to the underground right? In the story you are describing, even though it is in the past, you are describing a continuing action. So, because you were walkING, the father was also talkING to his child, right? Just be clear, too, on who was passing the yard: was it you or them? Let me know if you need further explanation!