There are several ways of writing. I write パーティー with "pa-thi-", we have the sound with the normal letter and the small letter together. Ex.) きゃ、きゅ、きょ(kya, kyu, kyo) ウィ、ウェ、ウォ(whi, whe, who), ティ(thi)、ディ(dhi) You can write only the small letters with "l" of little and "a, i, u, e, o, ya, yu, yo". ぁ、ぃ、ぅ、ぇ、ぉ、ゃ、ゅ、ょ(la, li, lu, le, lo, lya, lyu, lyo) To write small っ, please type double "tt" or every other consonant, then you get rid off the last consonant if you don't need. Ex.) かった(katta), インターネット(inta-netto), うわっ(uwatt then get of the last "t") I hope this helps you.