I is one, singular means one.
The noun 'use' is singular noun. The plural form is uses.The word 'use' is also a verb: use, uses, using, used.
Phenomena is a plural noun. The singular form is phenomenon. There is some tendency to use phenomena as a singular noun, but it is not actually a legitimate form.
The singular form of feet is foot.
The singular form is hilum.
The form plumber is the singular form; the plural form is plumbers.
We use is in singular form and are in plural form.
You would use the singular form of gustar, which is gusta, with a singular noun. For example, "Me gusta la pizza" (I like pizza).
Antenna
The singular form of "studies" in the sentence "she studies her book" is "study".
Use the singular form when referring to one specific item or individual. Use the plural form when referring to more than one item or individual. Remember to match the verb, pronouns, and articles accordingly with either singular or plural nouns in a sentence.
This is used in singular form while these is used in plural form.
The word 'criteria' is the plural form of the singular word 'criterion'. 'Those are the criteria that I used in making my decision.' 'That is the criterion that I used in making my decision.' It is wrong to use the word 'criteria' as a singular. Similarly, it is wrong to use 'phenomena' as a singular. It is the plural form of the singular word 'phenomenon'.
The noun 'use' is singular noun. The plural form is uses.The word 'use' is also a verb: use, uses, using, used.
The singular form of the demonstrative pronoun 'these' is this.
Phenomena is a plural noun. The singular form is phenomenon. There is some tendency to use phenomena as a singular noun, but it is not actually a legitimate form.
We use are when the sentence is in plural and is when the sentence is in singular form.
The singular form of "that" is "it."