El profesor sonríe al ver a sus alumnos.

The professor smiles when he sees his students.

Breakdown of El profesor sonríe al ver a sus alumnos.

• su: his
• a: to
• el profesor: the professor
• sonreír: to smile
• el alumno: the student

Questions & Answers about El profesor sonríe al ver a sus alumnos.

What does the phrase al ver mean, and why is it used in its particular structure in this sentence?

Al ver is a common Spanish construction that literally combines a with the infinitive ver. In this construction—often rendered in English as “upon seeing” or “when [he] sees”—the al + infinitive structure indicates that one action (the professor smiling) occurs when another action (seeing his students) takes place. It neatly links the time of the actions without the need for a separate conjunction.

Why is the direct object a sus alumnos preceded by the preposition a?

In Spanish, when the direct object of a verb refers to people (or sometimes pets or personified entities), the preposition a must be used before it. Here, sus alumnos (his students) are people, so a is used to mark them as the direct object of the action embedded in al ver.

What is the tense and mood of sonríe, and how does it relate to the sentence’s overall meaning?

The verb sonríe is in the present indicative form and is conjugated in the third person singular to agree with El profesor. This tense is used to describe either a habitual action or an action occurring at the moment of speaking. In this sentence, it tells us that the professor smiles in response to seeing his students, linking the timing of both actions in a natural, immediate way.

Why is ver left in the infinitive form instead of being conjugated like sonríe?

In the al + infinitive construction, the infinitive always follows the preposition al. This structure is a fixed grammatical pattern in Spanish that expresses a condition or simultaneous action (similar to “upon doing” in English). Conjugating ver would break this pattern and would not express the intended meaning of an instantaneous or habitual reaction.

What function does the possessive adjective sus serve in a sus alumnos?

The possessive adjective sus indicates ownership or association, specifying that the students belong to or are connected to El profesor. In this context, it translates to “his” in English. Although sus can sometimes be ambiguous (it might mean his, her, or their), the context provided by El profesor makes clear that the students are his.

Is it possible to rearrange the sentence, for example by placing al ver a sus alumnos at the beginning, without changing the meaning?

Yes, rearranging the sentence to “Al ver a sus alumnos, el profesor sonríe.” is grammatically correct and maintains the same meaning. The different word order can shift the emphasis slightly—for example, highlighting the condition ("upon seeing his students") first—but the overall message remains unchanged.