you've got to know first its root word which is "sadya" to mean:
'purpose': "ano ang sadya mo dito?" ('what are you here for?' / what's your purpose of going here?')
'reality (in a high degree)': "sadya na napakaganda niya" ('she's really so beautiful.')
'designed / planned': 'sadya na ganyan ang pagkakagawa niyan." ('It was built as planned.')
"sinadya" is an adjective to mean 'intentional' or 'deliberate'
"sinadya ko na basagin ang salamin" - 'I intentionally broke the mirror.'
:)