thoraces
Most nouns form their plural by adding "s" to the end of the word.
The plural form for the demonstrative pronoun this is these.
The plural word of delay is delays.
The plural noun is raisins.
The correct plural for the word "wolf" is "wolves."
The form thorax it the singular; there are two accepted plural forms: thoraxes or thoraces.
An insect's body is attached to the thorax.
The definition of thoracic is "of or relating to the thorax." There is no noun form of "thoracic" as the word is naturally an adjective, but the thorax is what the word is referrencing.
Fenêtres (fem. plural) means 'windows' in English.
Plankton is plural and its singular form is plankter. However, be aware that the word "plankton" is most often used in its plural as a collective noun.
The plural of the word piano is pianos. Most nouns have an S added to them to make them plural.
The word crises is a plural word; it is the plural form of the word crisis.
thorax
Since there is only one Texas, a plural form would not be of any use. But if someday there were a second Texas, it is most likely that "Texases" would be used as the plural. But language sometimes develops in unexpected ways. It is possible that some other form might gain popular acceptance if such a word is ever needed.
Most nouns form their plural by adding "s" to the end of the word.
There is no plural word for if.
The word octopuses is a plural for for the singular octopus. Another plural form is octopi. Both plurals are accepted and in most dictionaries.