This is the 727th most frequent Lithuanian word.
pirmosios
"First" (feminine plural form).
Here, 'pirmosios' is used as a nominative plural form of the adjective 'pirmoji,' modifying the noun 'kregždės' (swallows). It denotes the initial swallows returning in spring.
Pirmosios kregždės grįžo pavasarį.
The first swallows returned in the spring.
In this sentence, 'pirmosios' functions in the nominative plural feminine form, describing the noun 'dienos' (days). This implies the initial days of her school experience.
Tai buvo pirmosios jos mokyklos dienos.
Those were the first days of her school.
The term 'pirmąsias' is used here in the accusative plural feminine form, modifying 'varžybas' (competitions). This denotes the initial competitions where the meeting occurred.