Learn Spanish (Latin America): Los doctores comen manzanas.

In Spanish, when a noun ends in a consonant like the letter "r" in doctor, you make it plural by adding -es. That is why doctor becomes doctores.

Why does manzanas only get an -s instead of -es?

Because the singular word manzana ends in a vowel. For nouns ending in a, e, i, o, or u, you simply add an -s to make them plural, just like we usually do in English.

Why use los instead of el at the beginning of the sentence?

Words for "the" have to match the noun they describe. Because doctores is a plural and masculine group, the singular masculine word el must change to its plural form, los.

Why does the verb change to comen?

Comen is the form of the verb comer (to eat) that goes with "they". Since "the doctors" acts as a "they" in this sentence, we drop the -er and add the plural ending -en.