La palabra después del punto empieza con mayúscula, no con minúscula.

Because del is the normal contraction of de + el in Spanish.

• de + el = del
• So después del punto = after the period / full stop

This contraction is required in standard Spanish, except when el is part of a proper name, such as de El Escorial.

Here punto means the full stop / period in writing.

In other contexts, punto can also mean:

• point
• dot
• stitch
• moment or point in a discussion

But in this sentence, because it talks about capital and lowercase letters, punto clearly means the punctuation mark .

La palabra means the word. It is the subject of the sentence:

• La palabra ... empieza ...
• The word ... starts ...

Spanish often uses the definite article more freely than English. So La palabra después del punto literally means The word after the full stop.

Because después de normally takes a noun with an article when you mean a specific thing.

• después del punto = after the full stop / after the period
• después de la clase = after class
• después del almuerzo = after lunch

Using del here makes it sound natural and specific.

Because the subject is singular: La palabra.

• La palabra empieza = The word starts
• Las palabras empiezan = The words start

So the verb must agree with the singular noun palabra.

Because the idea is starts with a capital letter, not is uppercase in general.

• empieza con mayúscula = begins with a capital letter
• empieza con minúscula = begins with a lowercase letter

Spanish commonly uses empezar con to talk about how a word begins.

Here they are being used as nouns, shortened from expressions like:

• letra mayúscula = capital letter
• letra minúscula = lowercase letter

Since letra is feminine, the adjectives mayúscula and minúscula appear in the feminine form. Over time, they are often used on their own:

• con mayúscula
• con minúscula

This is very common and natural.

Because in Spanish these are set expressions.

• escribir con mayúscula
• escribir con minúscula

They mean to write in capitals / lowercase or with a capital / lowercase letter. Spanish usually does not say con la mayúscula here.

Yes. Empezar and comenzar both mean to begin / to start.

So you could say:

• La palabra después del punto empieza con mayúscula.
• La palabra después del punto comienza con mayúscula.

Both are correct. Empieza is often a bit more everyday and common in speech.

Because Spanish often avoids repeating information that is already clear.

The full version would be:

• La palabra después del punto empieza con mayúscula, no empieza con minúscula.

But that sounds repetitive, so Spanish shortens it to:

• ..., no con minúscula.

English does the same sometimes:

• It starts with a capital letter, not with a lowercase one.

Con means with.

In this sentence, it links the verb empieza to the type of letter the word begins with:

• empieza con mayúscula = starts with a capital letter
• empieza con minúscula = starts with a lowercase letter

So con is necessary because Spanish expresses this idea as to begin with X.

They are both stressed on the third-to-last syllable:

• ma-YÚS-cu-la
• mi-NÚS-cu-la

Words stressed on the third-to-last syllable are called esdrújulas, and in Spanish they always take a written accent mark.

So:

• mayúscula
• minúscula

must both be written with accents.

Yes. In Spain, punto is the normal word for full stop / period.

You may also hear more specific terms in grammar or spelling, such as:

• punto final
• punto y seguido
• punto y aparte

But in a general sentence like this, punto is the standard and natural word.