I want some of you to come up here and talk about your/their worries to your classmates. The other students should give some tips on the problems/worries/matters. Then they/you should add the expression "Everything will be okay." After that the student who told his or her worry to the others should say, "I will. Thank you!" Can you do that? OK. Does anyone want to tell us his or her worry in the front? Raise your hand, please. OK. Comu py here and facing your classmates, tell your worry.

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This is a pasage about an activity. Would you identify correct expression and correct any errors?

Well, you do have a typo in here. "Comu py"??? I think you mean "Come up". :)

More seriously, the only fault I can see is "I will Thank You." Do you mean the student will someday, in the future, say "Thank you"? or do you mean he or she should say "Thank you" in the moment for what has just been said and done? "I will" means some time in the future, not right now.

I want some of you to come up here and talk about your/their worries to your classmates. The other students should give some tips on the problems/worries/matters. Then they/you should add the expression "Everything will be okay." After that the student who told his or her worry to the others should say, "I will. Thank you!" Can you do that? OK. Does anyone want to tell us his or her worry in the front? Raise your hand, please. OK. Come up here, and facing your classmates, tell your worry.

Thank you for your help.

Can we use all the words with slashes? Would you check them?

In informal writing, the slashes are fine. In formal writing, and certainly in speech, we would say "he or she". We would not say "he slash she".

And, I see what you mean with "I will. Thank you." You seem to mean the student should say, "I will be okay. Thank you." You might make that clearer.

I want some of you to come up here and talk about their worries to your classmates. The other students should give some tips on the problems(worries/matters). Then they should add the expression "Everything will be okay." After that the student who told his or her worry to the others should say, "I will. Thank you!" Can you do that? OK. Does anyone want to tell us his or her worry in the front? Raise your hand, please. OK. Come up here, and facing your classmates, tell your worry.

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Thank you for your help....I deleted some. Is this passage grammatical? Can we use 'problems', 'worries', and 'matters' in this situation?

I think this is much better than the earlier version. It is simpler and clearer. Yes, "worries, problems, matters" can all be used together as you do here. "matters" is a little more vague than "worries" or "problems", but it works.