The correct spelling of plurals usually depends on what letter the singular noun ends in. 1 To make regular nouns plural, add s to the end. cat  cats. house  houses. 2 If the singular noun ends in s, ss, sh, ch, x, or z, you usually add -es to the end to make it plural.

We use this, that, these and those to point to people and things. This and that are singular. These and those are plural.