In Chinese, I often get these two/three characters confused:

  1. 殳 shū "halberd", which decomposes as 殳 ==> ⿱(几, 又).

    This is the (now rarely used) term for an ancient weapon. Often seen as the phonetic component in more common characters, such as 投 tóu "throw; fling".

  2. The right half of 船 chuán "boat", which decomposes as ? ==> ⿱(几, 口).

    This isn’t a character but an alternative way of writing 㕣 yǎn "marsh", which decomposes as 㕣 ==> ⿱(八, 口).

  3. 召 zhào "call; decree", which decomposes as 召 ==> ⿱(刀, 口).

    Common by itself in terms like 召开 zhàokāi "hold a meeting; convene", and as the phonetic component in 照 zhào "shine; illuminate", etc.

    This is easier for me to remember since “decreeing” something is like using your 口 kǒu "mouth" as a 刀 dāo "knife".