diff --git a/regex_humanizer/converter/converter.py b/regex_humanizer/converter/converter.py
index dccabdb..e20b9da 100644
--- a/regex_humanizer/converter/converter.py
+++ b/regex_humanizer/converter/converter.py
@@ -1,4 +1,6 @@
-from typing import List, Optional
+"""Implementation of regex to English conversion."""
+
+from typing import Any, List
 
 from ..parser import (
     Alternation,
@@ -15,6 +17,7 @@ from ..parser import (
 
 
 def quantifier_description(quantifier: Quantifier, child_desc: str) -> str:
+    """Generate description for a quantifier."""
     if quantifier.min == 0 and quantifier.max == 1:
         base = "optionally"
     elif quantifier.min == 0 and quantifier.max == Quantifier.MAX_UNBOUNDED:
@@ -37,6 +40,7 @@ def quantifier_description(quantifier: Quantifier, child_desc: str) -> str:
 
 
 def literal_description(node: Literal) -> str:
+    """Generate description for a literal character."""
     if node.value == " ":
         return "a space"
     elif node.value == "\t":
@@ -52,6 +56,7 @@ def literal_description(node: Literal) -> str:
 
 
 def character_class_description(node: CharacterClass) -> str:
+    """Generate description for a character class."""
     parts = []
 
     if node.inverted:
@@ -90,6 +95,7 @@ def character_class_description(node: CharacterClass) -> str:
 
 
 def special_sequence_description(node: SpecialSequence) -> str:
+    """Generate description for a special sequence."""
     sequences = {
         ".": "any single character",
         r"\d": "a digit (0-9)",
@@ -111,6 +117,7 @@ def special_sequence_description(node: SpecialSequence) -> str:
 
 
 def anchor_description(node: Anchor) -> str:
+    """Generate description for an anchor."""
     anchors = {
         "^": "the start of the string",
         "$": "the end of the string",
@@ -121,6 +128,7 @@ def anchor_description(node: Anchor) -> str:
 
 
 def group_description(node: Group) -> str:
+    """Generate description for a group."""
     if node.name:
         name_desc = f"named '{node.name}'"
     elif not node.capturing:
@@ -136,6 +144,7 @@ def group_description(node: Group) -> str:
 
 
 def alternation_description(node: Alternation) -> str:
+    """Generate description for an alternation."""
     option_descs = []
     for option in node.options:
         if option:
@@ -150,6 +159,7 @@ def alternation_description(node: Alternation) -> str:
 
 
 def backreference_description(node: Backreference) -> str:
+    """Generate description for a backreference."""
     if isinstance(node.reference, int):
         return f"whatever was matched by capture group {node.reference}"
     else:
@@ -157,6 +167,7 @@ def backreference_description(node: Backreference) -> str:
 
 
 def generate_description(nodes: List[ASTNode]) -> str:
+    """Generate a human-readable description for a list of AST nodes."""
     if not nodes:
         return "an empty pattern"
 
@@ -201,6 +212,15 @@ def generate_description(nodes: List[ASTNode]) -> str:
 
 
 def convert_to_english(pattern: str, flavor: str = "pcre") -> str:
+    """Convert a regex pattern to human-readable English.
+
+    Args:
+        pattern: The regex pattern to convert.
+        flavor: The regex flavor (pcre, javascript, python, go).
+
+    Returns:
+        A human-readable English description of the pattern.
+    """
     try:
         ast = parse_regex(pattern)
         return generate_description(ast)
@@ -209,10 +229,19 @@ def convert_to_english(pattern: str, flavor: str = "pcre") -> str:
 
 
 def convert_to_english_verbose(pattern: str, flavor: str = "pcre") -> dict:
+    """Convert a regex pattern to detailed structure.
+
+    Args:
+        pattern: The regex pattern to convert.
+        flavor: The regex flavor.
+
+    Returns:
+        A dictionary with pattern analysis.
+    """
     try:
         ast = parse_regex(pattern)
 
-        result = {
+        result: dict[str, Any] = {
             "pattern": pattern,
             "flavor": flavor,
             "description": generate_description(ast),
@@ -234,8 +263,9 @@ def convert_to_english_verbose(pattern: str, flavor: str = "pcre") -> dict:
         }
 
 
-def node_to_dict(node: ASTNode) -> dict:
-    result = {"type": type(node).__name__}
+def node_to_dict(node: ASTNode) -> dict[str, Any]:
+    """Convert an AST node to a dictionary."""
+    result: dict[str, Any] = {"type": type(node).__name__}
 
     if hasattr(node, 'position'):
         result["position"] = node.position