Estar com sono.

The phrase 'estar com sono' is a common idiomatic expression in Portuguese, directly translating to 'to be with sleep'. The verb 'estar' comes from the Latin 'stare', meaning 'to stand' or 'to be', and is used to describe temporary states. 'Com' is a preposition meaning 'with', derived from the Latin 'cum'. 'Sono' means 'sleep' and originates from the Latin 'somnus', which is related to the Greek 'hypnos' and the Sanskrit 'svapna', all referring to the state of sleep. The construction 'estar com' is frequently used in Portuguese to express a temporary physical or emotional state, such as 'estar com fome' (to be hungry) or 'estar com sede' (to be thirsty). This particular phrase has been in use for centuries, reflecting a natural and concise way to express the sensation of sleepiness in the Portuguese language. Its structure and meaning have remained consistent over time, making it a fundamental part of everyday communication in Portuguese-speaking cultures. The roots of 'somnus' can be traced back to Proto-Indo-European *swep-no-, further highlighting its ancient lineage across various Indo-European languages.