This is the 19th most frequent Indonesian word.
adalah
"Adalah" means "is" or "are" (used to equate or define something).
Here, 'adalah' acts as a linking verb that connects the subject 'Ini' with the predicate 'buku favorit saya', which describes it.
Ini adalah buku favorit saya.
This is my favorite book.
'Adalah' operates to introduce an explanation or definition related to a subject ('Pentingnya pendidikan').
Pentingnya pendidikan adalah sesuatu yang tidak dapat disangkal.
The importance of education is something that cannot be denied.
In this sentence, 'adalah' serves as a connecting verb within a statement, linking 'kebahagiaan' (a subject) to its description, 'pilihan'.