'Clothes' is a good example for this.
There can be no plural form of to. To is a preposition. there can only be plural forms of nouns.
There is no plural of the word toast. There is only 'pieces of' toast.
The word include does not have a plural as it is a verb. It is only nouns that have a plural form.
The word is "I" which becomes "is".
The word shiny is an adjective and so doesn't have a plural. It is only nouns that have a plural form.
No, the word plural means two or more. The word singular means only one.
The word young as an adjective has no plural. Only nouns have plurals. The word "young" to mean "young animals" is already a plural (collective) form.
The word explain is a verb. Verbs do not have plurals; only nouns (and pronouns) have plural forms.
No,the only word that comes close is piano, the plural of which is pianos
The word therefore is an adverb, not a noun, and has no plural. The plural "therefores" would only occur when referring to the word itself, as in "He uses too many therefores in his sentences."
The word shiny is an adjective and so doesn't have a plural. It is only nouns that have a plural form.
The noun "cattle" is only plural, never singular; a plural uncountable noun, a word for domesticated bovines as a group.