The plural form of "hay" is "hay." Unlike many nouns in English that change form in the plural, "hay" remains the same whether referring to one bale or multiple bales.
Hay mucho -masculine singular Hay mucha -feminine singular Hay muchos -masculine plural Hay muchas -feminine plural
We saw a team of oxen pulling a farmer's wagon of hay.
No hay acento en la forma plural de palabras que terminan en 'ción'. There is no accent mark in the plural form of words that end in 'ción"
The phrase "en la mesa hay mucho libros" is incorrect. It should be "en la mesa hay muchos libros" to match the plural form of "libros."
The plural form of lock is locks.
There is no plural form. Do and Do not are verbs
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
The plural form of "was" is "were."
The plural form of "I" is "we."
The plural form of "is" is "are."
The noun ox is the singular form; the plural form is oxen.