Thirty denotes more than one, so a plural noun should be used, and this sentence should be, The house is 30 feet square.
In many words, there is no difference in the sound between a single noun in the possessive form and a plural noun in the possessive form.
There are certain errors we often make, as for example, using a plural noun with a singular verb, or using the past time form of the verb for the past participle.
And these are the thoughts by which the Jews suffer themselves to be led away from this text; and which thus prevent them from believing in a plurality of persons in the deity; whereas it is evident that Moses employs a plural noun.
Why therefore does Moses here use a plural noun or name?
Nor does Moses place anything before "the beginning" but God himself; and him he here represents by a plural noun.
Hence, that, as well as the, was formerly used, indifferently, before either a singular or a plural noun.
You perceive that the participle sailing refers to a singular noun in the first example, and to a plural noun in the second; and yet the participle is in the same form in both examples.
You was formerly restricted to the plural number; but now it is employed to represent either a singular or a plural noun.
To insert neither, unless we make a close compound, is to use a plural noun adjectively; which form, I think, is the most objectionable of all.
The article an or a must never be so used as to relate, or even seem to relate, to a plural noun.
Why may we not form a plural noun news from new, to express the same idea which in Latin is expressed by nova, and in French by les nouvelles?
Why may we not have a plural noun riches, as the Romans had divitæ, and the Germans have die Reichthumer?
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "plural noun" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
