El puente gigante cruza el río.

In Spanish, singular countable nouns normally require an article (definite or indefinite) when they function as subjects or objects. Here, el puente means “the bridge,” pointing to a specific or known bridge. In English you might drop “the” in headlines or poetic speech, but Spanish needs that article.

The default Spanish word order for descriptive adjectives is noun + adjective. So you normally say puente gigante rather than gigante puente. Placing an adjective before the noun can add emphasis or a poetic tone, but for most neutral descriptions you keep it after.

Spanish uses the simple present tense to express:
• habitual actions (“El autobús cruza el río todos los días”)
• general truths or facts (“El puente cruza el río”).
The present progressive (está cruzando) is reserved for actions happening right at this moment and feels more immediate.

The verb cruzar can take a direct object without any preposition: cruzar algo “to cross something.” Since el río is the direct object here, no extra preposition is needed. If you said caminar sobre el río, that would mean “to walk on top of the river,” which is a different idea.

Spanish spelling rules say:
• Words ending in a vowel, n or s are normally stressed on the next-to-last syllable.
• río is two syllables (rí-o), but if it followed the normal rule it would be pronounced as one diphthong (/rio/).
• The accent mark forces the break: rí-o and marks that the stress is on the first syllable.

Nouns ending in -e can be either gender, so you usually have to memorize them or look them up. For puente, usage shows it’s masculine, so we pair it with el and adjectives like gigante don’t change ending (since gigante is the same for both genders).

Yes, grammatically you could say:
El río es cruzado por el puente gigante.
However, Spanish often prefers the active voice. That passive form is correct but sounds more formal or bookish.