This is the 8192nd most frequent Russian word.
ля
The Russian word "ля" refers to the musical note "A" in English.
The word 'лёг' is used here as the past tense of 'лягу' (to lie down).
Я лёг на кровать, чтобы отдохнуть.
I lay down on the bed to rest.
'Лягла' is the feminine past tense form of the verb 'лягу,' meaning 'lie down.'
Кошка лягла на диван и уснула.
The cat lay down on the couch and fell asleep.
The imperative form of 'лягу' is used, which is 'ляг', instructing someone to lie down.