how can you tell when a word is singular o plural

Question

how can you change a word from singular to plural ex. the word un diario

Answer 1

plural nouns in Spanish

The above article explains what covers 99% of the singular/plural noun forms.

Then just to make a simple concept complex they introduce mass nouns, nouns that are singular in Spanish, but plural in English (la gente), nouns that are normally used only in plural or singular from (las mátematicas), nouns that change spelling when you change their number (lapiz, lapices) and a sundry of other anomalies just so you don't become complacent or confident.

lápiz / lápices, with accent. But this is no anomaly: practically all words ending in -z form their plural with -ces. This is a general rule about the use of Z and C. - lazarus1907, Aug 28, 2010

Sorry, a poor (hyperbolie) choice of words. - 0074b507, Aug 28, 2010

Answer 2

Simple: because nearly no singular word ends in -s (probably none, but I don't want to bet). There are no words like mice, fleet, syllabi or data which are plural but have no -s at the end.

el paraguas el parabrisas el abrelatas (invariable words) - 0074b507, Aug 28, 2010

Answer 3

Hii! Welcome to the forum. Well , you can find it on the internet , right?

El gato = Los Gatos

La cucaracha = Las cucarachas