Subjects can be divided into 6 categories depending upon "person" and "plurality"
"person" refers to whether the subject is
color(white)("XXX")XXXthe person(s) making the statement: first person
color(white)("XXX")XXXthe person(s) to whom the statement is being directed: second person
color(white)("XXX")XXXany other person/thing: third person.
""plurality" refers to the number of individuals included in the subject:
color(white)("XXX")XXXone individual: singular
color(white)("XXX")XXXmore than one individual: plural
{:
("first person singular:", color(blue)("I")),("first person plural:",color(blue)("we")),
("second person singular:",color(blue)("you") " [or in Old English: "color(blue)("thou")"]"),
("second person plural:", color(blue)("you")),
("third person singular:", color(blue)("he, she, it" color(black)(or) "a named person/item")),
("third person plural:",color(blue)("they" color(black)(or) "a named group of people/items"))
:}
The verb used (especially in the present tense) may vary depending upon the category of the subject. This is called subject-verb agreement.
In many cases (in the present tense) the only variation of the verb is an addition of an "s" to the end of the verb for third person singular:
For example:
color(white)("XXX")I run;
color(white)("XXX")you run;
color(white)("XXX") she runs;
color(white)("XXX")we run;
color(white)("XXX")you run;
color(white)("XXX")they run.
There may be some variation to this general rule even for "regular" verbs. For example "go" rarr "goes"; and "have" rarr "has".
A few verbs are irregular in this respect, especially the verb "to be"
color(white)("XXX")I am
color(white)("XXX")you are [or in Old English: thou art]
color(white)("XXX")he/she/it is
color(white)("XXX")we are
color(white)("XXX")you are
color(white)("XXX")they are
