The non-count noun 'string' takes a singular verb form; for example:
The string is tied too tight.
The string is in the top drawer.
Some nouns that are the same for the singular and the plural are:deerfishelksheepoffspringSome nouns are singular but appear to be plural; words that are a short form for 'a pair of...'. There is no plural for these nouns, the plurals are expressed by using 'pairs of...'. Some examples are:pantsshortsglassesscissorsbinocularsUncountable nouns have no plural form and take a verb for the singular. Some uncountable nouns are:moneyinformationnewsadviceelectricity
The verb reviewed is used after both singular and plural nouns.
Since equipment is uncountable, it would take a singular verb. Equipment "is," but pieces of equipment "are."
'Discuss' is a verb. In english, only nouns and pronouns have singular and plural forms. the verb discuss can be used with both singular nouns and pronouns (I discuss) and plural nouns and pronouns (we discuss).
The word information is a mass or uncountable noun which, in most cases, take a singular verb.
The word 'watching' is the present participle of the verb to watch (I am watching, they are watching). The present participle of the verb is also an adjective (the watching crowd), and a gerund, a verbal noun. Gerunds are uncountable nouns.
No. The verb or helper verb "has" is singular. Plural nouns (and I and you) use "have."
As an auxiliary verb will is without number: He will go; they will go. As a main verb, it may be singular or plural: I will this to my heirs; they will it to their heirs.
Singular nouns that end with 's' which require a singular verb are:abyssaddressbasisbiasbrassChristmasclassdressdaisElvisempressfocusflossgrassglosshiatushumusibisirisisthmuskissKansaslosslotusmassMarsmessmissnarcissusnemesisonusopuspajamaspantspusplusrhombusruckusstresssassafrasspeciestosstennistresstrousersUranusunderpassviruswalrusZeus
Verbs cannot be singular or plural. Requires is after singular nouns.
Pronouns such as he, she, it, and singular nouns take a singular form of the verb. For example, "He goes to school" or "She eats fast."
"Has" is singular, e.g. He has, she has. "Have" is plural, e.g. They have, we have. The exception is "I" - e.g. I have.