The singular noun is oasis.
The plural noun is oases.
The plural of oasis is oases.
The plural of "oasis" is "oases."
The singular form is oasis, the plural form is oases.
The singular form of the plural noun 'oases' is oasis.
The singular form of Oases is, Oasis.
Oases is already plural. The singular is oasis.
The plural of crisis is "crises" (pronounced "cry-seez").
The plural form of oasis is oases.Oases
The singular possessive form of "oasis" is "oasis's."
Vita is singular. The plural form of vita is vitae
"Is" is the singular form of the verb "to be," used with singular subjects. "Are" is the plural form used with plural subjects.
It is singular. The plural is ellipses.