Questions & Answers about Tutanak masada.
Turkish location suffixes follow two harmony rules:
• Consonant harmony: after a vowel you use d, after a voiceless consonant you use t.
• Vowel harmony: choose a, e, ı, or i to match the last vowel of the noun (back vs. front, rounded vs. unrounded).
Since masa ends in the vowel a, you attach d + a → -da.