diff --git a/.changeset/young-bears-double.md b/.changeset/young-bears-double.md
new file mode 100644
index 00000000..291c0a2c
--- /dev/null
+++ b/.changeset/young-bears-double.md
@@ -0,0 +1,5 @@
+---
+"es-hangle": patch
+---
+
+refac: convertQwertyToHangul split 및 Non-null assertion operator 제거, 네이밍 오타 수정
diff --git a/src/convertQwertyToHangulAlphabet.ts b/src/convertQwertyToHangulAlphabet.ts
index f172ed35..bcc4aa81 100644
--- a/src/convertQwertyToHangulAlphabet.ts
+++ b/src/convertQwertyToHangulAlphabet.ts
@@ -27,5 +27,5 @@ export function convertQwertyToHangul(word: string): string {
   if (!word) {
     return '';
   }
-  return assembleHangul([...convertQwertyToHangulAlphabet(word).split('')]);
+  return assembleHangul([...convertQwertyToHangulAlphabet(word)]);
 }
diff --git a/src/disassembleCompleteHangulCharacter.ts b/src/disassembleCompleteHangulCharacter.ts
index 36220bbd..3cb5c7a5 100644
--- a/src/disassembleCompleteHangulCharacter.ts
+++ b/src/disassembleCompleteHangulCharacter.ts
@@ -32,8 +32,8 @@ export function disassembleCompleteHangulCharacter(
   const firstIndex = Math.floor((hangulCode - lastIndex) / NUMBER_OF_JONGSUNG / NUMBER_OF_JUNGSUNG);
 
   return {
-    first: HANGUL_CHARACTERS_BY_FIRST_INDEX[firstIndex]!,
-    middle: HANGUL_CHARACTERS_BY_MIDDLE_INDEX[middleIndex]!,
-    last: HANGUL_CHARACTERS_BY_LAST_INDEX[lastIndex]!,
+    first: HANGUL_CHARACTERS_BY_FIRST_INDEX[firstIndex],
+    middle: HANGUL_CHARACTERS_BY_MIDDLE_INDEX[middleIndex],
+    last: HANGUL_CHARACTERS_BY_LAST_INDEX[lastIndex],
   } as const;
 }
diff --git a/src/removeLastHangulCharacter.ts b/src/removeLastHangulCharacter.ts
index 6d4f0034..944fc331 100644
--- a/src/removeLastHangulCharacter.ts
+++ b/src/removeLastHangulCharacter.ts
@@ -18,14 +18,14 @@ import { excludeLastElement } from './_internal';
  * removeLastHangulCharacter('일요일') // 일요이
  */
 export function removeLastHangulCharacter(words: string) {
-  const disassembedGroups = disassembleHangulToGroups(words);
-  const lastCharacter = disassembedGroups.at(-1);
+  const disassembledGroups = disassembleHangulToGroups(words);
+  const lastCharacter = disassembledGroups.at(-1);
 
   if (lastCharacter == null) {
     return '';
   }
 
-  const withoutLastCharacter = disassembedGroups
+  const withoutLastCharacter = disassembledGroups
     .filter(v => v !== lastCharacter)
     .map(([first, middle, last]) => {
       if (middle != null) {