El niño valiente cruza la calle solo.

Most descriptive adjectives in Spanish follow the noun they modify: • niño valiente = “brave boy”
• Placing the adjective before (e.g. valiente niño) shifts the emphasis or adds a poetic/stylistic nuance. In neutral, everyday speech, you’ll usually find the adjective after the noun.

Position and context both matter: • El niño cruza la calle solo → solo comes after the verb and refers back to the subject (the boy), so it means “alone.”
• If you wrote El niño solo cruza la calle, solo would precede the verb and most likely mean “only,” implying “the boy only crosses the street (and does nothing else).”
Modern Spanish no longer uses an accent on solo, even when it means “only,” so word order and context are your best clues.

This is the present‐tense, third‐person singular form of cruzar (to cross): • Stem: cruz-
• Ending for él/ella/usted: -a
Spanish verbs ending in -zar change z→c before an e (e.g. cruce in subjunctive), but before a the z stays the same, giving cruza.

• niño is masculine singular → article el
• valiente is an adjective that doesn’t change for gender (ends in -e), so it stays valiente for both masculine and feminine.
• calle is feminine singular → article la
• solo as “alone” here functions adverbially and stays invariable. If you used solo adjectivally before/after a noun (e.g. niño solo, niña sola), it would agree in gender.