There are some cases of verbs where agreement causes doubt. Here are the special cases, separately:
the verb to be
The) When the subject is one of the pronouns: o, this, this, that, everything, the verb to be agrees with the predicative:
Example: Everything was happiness when I lived at grandpa's house.
B) When the predicative is a personal pronoun.
Example: The gift I bought today is for you.
ç) When the subject is a person's name or personal pronoun, the verb to be will agree with the subject.
Example: Paola is the most diligent student in the room.
d) When the subject is a numerical expression that gives the idea of a set, the verb will be singular.
Example: Four hours is not enough time to take the entrance exams.
and) When the sentence starts with the interrogative pronouns (Who, Who), the verb agrees with the subject.
Examples: Who is the person who can take justice into his own hands?
f) When the prayer indicates the day of the month, the verb agrees in the singular or in the plural, it will depend on the intention.
Examples: Today is (day) September 11th. (specific day)
Today is September 11th. (days elapsed to date)
The verbs hit, sound and give
When referring to the hours of the day, the above verbs agree on the number of hours.
Example: The clock rang a long time ago.
It's just been an hour, it's time to go.
The impersonal verbs to be and to do
Impersonal verbs are those that do not admit a subject and, therefore, are inflected in the 3rd person singular.
In the sense of existing or in the idea of elapsed time, the verb to exist is impersonal. Therefore, the verb will be singular.
Example: There is a vacant chair in the cafeteria. (sense of existing)
I haven't exercised for ten days. (elapsed time)
Likewise, the verb to do in the sense of time, of elapsed time or of atmospheric phenomena is impersonal.
Example: I haven't exercised for ten days. (elapsed time)
At this time of year, it's very cold.
When speaking, both the verb to exist and the verb to do require the auxiliary to be in the third person singular.
Examples: There must be a way to alleviate this problem.
I haven't exercised for ten days.
the verb exist
Generally, the verb exist agrees with its subject.
Example: There are many people who don't like seafood.
When the verb exists is part of a verbal phrase, the auxiliary will agree with the subject and not with the main verb.
Example: There must be a lot of people who don't like seafood.
the verb to seem
When the verb appears to be followed by an infinitive, it can be inflected either in the singular or in the plural:
Examples: The surveys seem to translate what the company needs.
The surveys seem to translate what the company needs.
The expression "in view"
The verb to exist in the expression “haja vista” can be used either in the singular or in the plural (provided it is not preceded by a preposition), however, the word “vista” remains invariable.
Examples: In view of the survey data
In view of the advances observed by researchers.
In view of the data we have observed.
By Sabrina Vilarinho
Graduated in Letters
See more!
Verbal Agreement - The special cases of the compound subject
When the subject is composed, how is verbal agreement done? Click here and find out!
Source: Brazil School - https://brasilescola.uol.com.br/gramatica/concordancia-verbalcasos-especiais-alguns-verbos.htm