Step 1: Understanding the context.
The sentence means “Anyone can achieve their dreams if they are convinced of it.” In Spanish, “cualquiera” is used as an indefinite pronoun meaning “anyone.”
Step 2: Grammar explanation.
“Cualquiera” is used before a noun in a general sense or after it to mean “any” or “whoever.”
For example:
- Cualquiera persona puede hacerlo. (Any person can do it.)
Step 3: Analysis of options.
- (1) Cualquiera → Correct; used to mean “anyone.”
- (2) Cualquiera de → Used when referring to a specific group, e.g., “Cualquiera de ellos.”
- (3) Cualquier → Used before singular nouns but requires direct noun (e.g., “cualquier persona”), not with “una.”
- (4) Cualesquieres → Rare plural form, not used in this context.
Step 4: Conclusion.
Therefore, the correct expression is “Cualquiera persona puede cumplir sus sueños si está convencido de ello.”