Every one, when he stops to think, knows that the words those and these mean more than one. Still it is a very common mistake to use them in speaking of only one. In which of these sentences are they used correctly?

1. I do not like those kind of grapes. (How many kinds?)

2. I do not like those kinds of grapes.

3. Those sorts of persons are both trying.

4. These kind of apples bake well.

5. These kinds of corn do not ripen early enough.

What should be used instead of those and these in sentences one and four?

Write sentences in which you use this kind, that kind; this sort, and that sort.