Learn Spanish (Latin America): Yo como manzanas y tú comes pan.

In Spanish, verb endings change depending on who is doing the action. For regular verbs that end in -er (like comer, to eat), the "I" form drops the -er and adds -o (yo como). The informal "you" form drops the -er and adds -es (tú comes).

Do I always need to include the words yo and tú?

No! Because the verb endings (-o and -es) already tell us exactly who is eating, you could just say Como manzanas y comes pan. However, speakers often include the subject words (yo and tú) in a sentence like this to emphasize the contrast between what I do and what you do.

Why does tú have an accent mark on the 'u'?

The written accent tells apart two words that sound exactly the same. Tú (with the accent) means the person "you". Tu (without the accent) means "your", as in tu pan (your bread).

Why aren't there any words like "the" or "some" before manzanas and pan?

Just like in English, when you talk about eating things in general or an unspecified amount, you can often leave out words like "the" or "some". If you said como las manzanas, it would mean "I eat the apples", referring to specific apples instead of just apples in general.