1. The hospital is for certain people.

2. He has a certain problem.
3. He has a sure problem.
4. He is certain that the boy is diligent.
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Are they all grammatical? The meaning of 'certain' seems to be different. Does #2 mean #3? Is the meaning of 'certain' the same in #2 and #4?

•English - Writeacher, Saturday, November 15, 2014 at 9:00am
3 is not a standard phrasing; use 2.

In 1 and 2, 'certain' means 'specific' or 'particular.' In 4, 'certain' means 'sure.'
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Thank you for your help.

3. He has a sure problem.

Instead of this expression, what other expressions do we have to use?

1. He has a big problem.
2. He has a definite problem.
3. He has a real problem.
4. He has an unfailing problem.
5. He has a firm problem.
6. He has a sure problem.

These are fine:

1. He has a big problem.
2. He has a definite problem.
3. He has a real problem.
4. He has an unfailing problem. (<~~IF you mean it'll never be solved or fixed.)

In the sentence "He has a sure problem," the word "sure" is not commonly used to describe a problem. Instead, you can use other expressions to convey the same meaning, such as:

1. He has a big problem.
2. He has a definite problem.
3. He has a real problem.
4. He has an unfailing problem.
5. He has a firm problem.

These alternatives convey that the person's problem is significant or certain without using the word "sure," which is not typically used in this context.