"Seem" is a verb and does not have singular or plural forms. Its usage depends on the subject of the sentence; for example, "He seems happy" (singular) and "They seem happy" (plural). The verb agrees in number with the subject, but "seem" itself remains unchanged.
The word "seem" is not plural; it is a verb that functions in the present tense. It can be used with singular or plural subjects, as in "He seems happy" (singular) or "They seem happy" (plural). The form of the verb does not change based on the number of the subject.
You seem to have the singular and the plural lumped into one word. The singular is diagnosis; the plural is diagnoses. They are the singular and plural forms of a common, abstract noun.
practitioner is singular (plural practitioners)sofa is singular (plural sofas)satellite is singular (plural satellites)clips is plural (singular clip)dentist is singular (plural dentists)dollars is plural (singular dollar)article is singular (plural articles)magazines is plural (singular magazine)laminator is singular (laminators is plural)radios is plural (singular radio)
singular and plural
Singular: book / Plural: books Singular: cat / Plural: cats Singular: child / Plural: children Singular: foot / Plural: feet
Are is plural. "Is" is singular. For example, "There is a glove on the chair". That is singular. "There are gloves on the chair". That is plural.
"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.
The word team is singular; the plural form is teams.
Who may be singular or plural.
This is singular. These is the plural form.
These is plural, this is singular
'These' is the plural form of 'this'.