我想問 looking forward to 後面嗰個verb洗唔洗加ing

呢個係書信片語(PHRASE)，looking forward to seeing you soon. Or, looking forward to hearing you...即係第一位係唔岩。
Why?因為唔可以分開用和諗的，你嘗試找英文書信，全部都係咁寫。

looking forward to 後面個verb唔洗加ing, 但係如果係look forward to的話後面個verb就要加ing