In English adjectives are not inflected.
The singular form of the demonstrative pronoun 'these' is this.
The singular form of "that" is "it."
The garbled response was not intelligible. Correcting this sentence's structure will make it intelligible. How can you call that an intelligible response?
The singular form is cuff.
it is already in its singular form.
"Stratum" is the singular form of stratum. The plural form is "strata".
I am intelligible.
The form hypothesis is the singular form. The plural form is hypotheses.
A singular form of dice is a die
The singular form of feet is foot.
The singular form of Oases is, Oasis.
"Wash" is the singular form of "wash."