Question

complete the sentence with the correct plural.

charles j. van depoele, who invented electric

trolley

in 1885, invested
much of his time and money
experimenting with electricity; in 1878,
he created a lighting system for an
evening circus performance.

Explanation:

To form the plural of "trolley", we follow the rule for nouns ending in "y" preceded by a consonant. We change the "y" to "i" and add "es". So "trolley" (where "y" is preceded by "l", a consonant) becomes "trolleys"? Wait, no, wait. Wait, "trolley" - the base form, when pluralizing a noun ending in "y" with a consonant before "y", we do "y" to "i" + "es"? Wait, no, actually, "trolley" is a noun, and the plural of "trolley" is "trolleys"? Wait, no, let's check. Wait, "trolley" - the correct plural: for nouns ending in "y" with a consonant before "y", the plural is formed by changing "y" to "i" and adding "es"? Wait, no, "trolley" - "trolley" has "l" before "y", so consonant + y. So the plural should be "trolleys"? Wait, no, maybe I made a mistake. Wait, no, "trolley" - the plural is "trolleys"? Wait, no, let's confirm. Wait, "trolley" is a countable noun. The rule is: if a noun ends in "y" and the letter before "y" is a consonant, we change "y" to "i" and add "es". If it's a vowel before "y", we just add "s". So "trolley" - "l" is a consonant, so "trolley" becomes "trolleys"? Wait, no, "trolley" - "y" is after "l", so consonant + y. So the plural is "trolleys"? Wait, no, maybe I'm wrong. Wait, let's check the correct plural of "trolley". Actually, the plural of "trolley" is "trolleys" (some sources) or "trolleys" (yes, because "trolley" is a noun where the "y" is preceded by a consonant, but sometimes, for some nouns, people just add "s" even with consonant + y, but the standard rule is consonant + y: change y to i, add es. Wait, but "trolley" - let's see: "trolley" → "trolleys"? Wait, no, "trolley" is spelled t-r-o-l-l-e-y. So the "y" is at the end, preceded by "e"? Wait, no, "trolley" is t-r-o-l-l-e-y. So the letters before "y" are "e"? Wait, no, "trolley" is t (1), r (2), o (3), l (4), l (5), e (6), y (7). So before "y" is "e", which is a vowel. Oh! Wait, I made a mistake. "Trolley" ends with "ey"? No, "trolley" is t-r-o-l-l-e-y. So the last two letters are "ey"? No, "trolley" is spelled with "e" before "y". So "e" is a vowel, so when a noun ends with "y" and the letter before "y" is a vowel, we just add "s". So "trolley" → "trolleys". Wait, but let's confirm. The correct plural of "trolley" is "trolleys". So in the sentence, "electric trolley" should be pluralized as "trolleys" because he invented electric trolleys (multiple trolleys, I assume). So the correct plural is "trolleys".

Answer:

trolleys