The spelling of the word "gattis" is a bit tricky. In IPA phonetic transcription, it is pronounced as /ˈɡætɪs/. The first syllable is pronounced with a hard "g" sound, as in "go", followed by the short "a" vowel sound. The second syllable is pronounced with a short "i" vowel sound, and ends with the consonant cluster "tis". The spelling of "gattis" might seem counterintuitive, as the "t" in the second syllable is silent, but that's how it's spelled!