Learn Hardcore Spanish (Latin America): El capitán guía el barco por la costa. - The captain guides the boat along the coast.

In Spanish, verbs ending in -iar (like guiar) place the stress on the i in the third-person singular present (él/ella). To mark that non-standard stress, you add an acute accent: guía instead of guia.

Why is por used here instead of para?

Por expresses movement through or along a place (the route). Para expresses purpose, destination, or deadline. Since the captain is steering along the coast, we use por la costa (“along the coast”), not para la costa.

What’s the difference between guiar and llevar?

Guiar means “to guide” or “to steer,” focusing on controlling direction. Llevar means “to carry” or “to take” something/someone to a destination. If you want to emphasize navigation of the ship, you use guiar; if you simply emphasize transporting the ship, llevar could work, but it’s less precise for steering.

Why are the nouns preceded by the definite article el (as in el capitán and el barco)? Could I say un capitán guía un barco instead?

Using el makes them specific (“the captain,” “the ship”) or refers to a general known category. Un capitán guía un barco (“a captain is guiding a ship”) is grammatically correct but changes the nuance to “some captain” and “some ship.” Definite articles are common in Spanish when the context makes the reference clear.

Why is la costa singular (“la costa”) and not plural (“las costas”)?

La costa refers to the coastline as one continuous stretch. Las costas would imply multiple separate coastlines (e.g., different regions or countries). Here you mean “along the (single) coast” of a particular place.

How do I say “The captain is guiding the boat along the coast” using a continuous tense?

Use the present progressive:
El capitán está guiando el barco por la costa.

Can I drop the subject el capitán and just say Guía el barco por la costa?

You can omit a noun or pronoun subject in Spanish if context makes it clear, but then you’d still need a pronoun or verb form: (Él) guía el barco… Dropping el capitán entirely may sound abrupt or leave the listener wondering who’s steering.

How is capitán pronounced? Which syllable takes the stress?

Pronounce it [ka-pee-TÁN], with the stress on the last syllable (the á) because of the written accent.

Could I place por la costa before the verb, like El capitán por la costa guía el barco?

That order (S–P–V–O) is grammatically possible but highly unusual in everyday speech. Standard word order in Spanish is Subject–Verb–Object, then adverbial phrases (e.g., prepositional phrases) at the end:
El capitán guía el barco por la costa.