Estoy

Estoy is the first-person singular present indicative form of the Spanish verb estar, meaning "to be" in contexts that describe temporary states, locations, emotions, health, or ongoing actions. As a core verb, estar is used to convey conditions that can change, unlike ser, which expresses more permanent or inherent characteristics.

Etymology and form: Estar derives from Latin stare (to stand) and has developed into a highly irregular verb in Spanish. In the present tense, the forms are: yo estoy, tú estás, él/ella está, nosotros estamos, vosotros estáis, ellos están. The yo form estoy is distinct from other verbs and participates in many common expressions and constructions.

Usage: The present of estar is used for location (Estoy en casa), temporary conditions (Estoy cansado), health (Estoy bien), and emotions or temporary states (Estoy feliz). It is also used to form the progressive aspect with a gerund, as in estoy leyendo (I am reading) or estoy trabajando (I am working). Additionally, estar appears in set phrases that express agreement, intention, or mood, such as Estoy de acuerdo (I agree) or Estoy pensando (I am thinking).

Comparison with ser: Estar describes conditions and locations that can change; ser describes stable properties, identity, origin, or time. Choosing between estar and ser can alter meaning, making this distinction central to correct usage.

See also: Estar, Ser (grammar), Spanish verbs.