Observasteis

Observasteis is the second-person plural form of the verb observar in the pretérito indefinido (simple past) tense in Spanish. It is used with the subject vosotros and translates to “you all observed” in English, indicating a completed action in the past.

Morphology and conjugation: Observasteis is formed from the verb stem observar plus the regular preterite endings for -ar verbs: -asteis for vosotros. Therefore it is a regular form, not irregular. The corresponding forms for other subjects are obser­vé, observaste, observó, observamos, observaron.

Regional usage: The vosotros form is standard in Spain and in some contexts among speakers who use the informal plural second person. In most of Latin America, ustedes replaces vosotros, and the corresponding preterite is observaron. As a result, observasteis is less common outside of Spain, though it may appear in literature, classroom material, or casual speech among speakers who use the vosotros form.

Example: Ayer observasteis las aves desde la ventana. This sentence illustrates the use of observasteis with vosotros to describe a past, completed action.

Etymology and related forms: Observasteis derives from the Latin observare, meaning to watch or to observe. Related forms include observé, observaste, observó, observamos, observaron, all serving the expressiveness of the same verb in different persons and tenses.

See also: observar, pretérito indefinido, vosotros.