how can i learn that lunettes is plural? is there a singular word for lunettes?

Bonjour Lea,

Lunettes is just like "eyeglasses" in English - they are both plural. The "s" at the end usually means that the word is plural, but there are exceptions.

There are many words like this in both languages. Sometimes they're both plural and sometimes the noun is plural in one language but not the other, such as les épinards = "spinach." This is just something you need to learn along with the new words.

https://www.french-test.com/revision/grammar/how-some-plural-nouns-in-english-are-singular-in-french-and-vice-versa

Please pardon my mistake. I made a big error. What I meant to ask was, how can I know that this plural word, lunettes, is feminine? The question called for knowing this.
Thank you for your explanation though.
Lea

Dear Lea,

You can hardly ever 'guess' the gender of a word unfortunately... however, in that case, you can remember that ALL words ending in '-ette' are feminine in French, so here you are.
For other gender tips, have a look at this lesson:
https://www.french-test.com/revision/grammar/how-to-identify-gender-by-some-word-endings

I hope it's helpful!