diff --git a/markdown_it/common/normalize_url.py b/markdown_it/common/normalize_url.py
index e3c4742b..c7504c7b 100644
--- a/markdown_it/common/normalize_url.py
+++ b/markdown_it/common/normalize_url.py
@@ -38,14 +38,14 @@
 )
 
 
-def unescape_char(s):
+def unescape_char(s: str) -> str:
     if s[0] == "\\":
         return s[1]
     else:
         return html.unescape(s)
 
 
-def unescape_string(s):
+def unescape_string(s: str) -> str:
     """Replace entities and backslash escapes with literal characters."""
     if re.search(reBackslashOrAmp, s):
         return re.sub(reEntityOrEscapedChar, lambda m: unescape_char(m.group()), s)
@@ -53,7 +53,7 @@ def unescape_string(s):
         return s
 
 
-def normalize_uri(uri):
+def normalize_uri(uri: str) -> str:
     return quote(uri.encode("utf-8"), safe=str("/@:+?=&()%#*,"))
 
 
@@ -63,7 +63,7 @@ def normalize_uri(uri):
 RECODE_HOSTNAME_FOR = ("http", "https", "mailto")
 
 
-def unescape_normalize_uri(x):
+def unescape_normalize_uri(x: str) -> str:
     return normalize_uri(unescape_string(x))
 
 
@@ -166,7 +166,7 @@ def normalizeLinkText(link):
 GOOD_DATA_RE = re.compile(r"^data:image\/(gif|png|jpeg|webp);")
 
 
-def validateLink(url: str, validator: Optional[Callable] = None):
+def validateLink(url: str, validator: Optional[Callable] = None) -> bool:
     """Validate URL link is allowed in output.
 
     This validator can prohibit more than really needed to prevent XSS.
diff --git a/markdown_it/common/utils.py b/markdown_it/common/utils.py
index 8ff69e1c..a2162ed8 100644
--- a/markdown_it/common/utils.py
+++ b/markdown_it/common/utils.py
@@ -197,7 +197,7 @@ def escapeRE(string: str) -> str:
 # //////////////////////////////////////////////////////////////////////////////
 
 
-def isSpace(code):
+def isSpace(code) -> bool:
     return code in {0x09, 0x20}
 
 
@@ -216,7 +216,7 @@ def isSpace(code):
 }
 
 
-def isWhiteSpace(code):
+def isWhiteSpace(code: int) -> bool:
     r"""Zs (unicode class) || [\t\f\v\r\n]"""
     if code >= 0x2000 and code <= 0x200A:
         return True
@@ -231,7 +231,7 @@ def isWhiteSpace(code):
 
 
 # Currently without astral characters support.
-def isPunctChar(ch):
+def isPunctChar(ch: str) -> bool:
     return UNICODE_PUNCT_RE.search(ch) is not None
 
 
diff --git a/markdown_it/helpers/parse_link_destination.py b/markdown_it/helpers/parse_link_destination.py
index 82955d08..4e91cb4f 100644
--- a/markdown_it/helpers/parse_link_destination.py
+++ b/markdown_it/helpers/parse_link_destination.py
@@ -15,7 +15,7 @@ def __init__(self):
         self.str = ""
 
 
-def parseLinkDestination(string, pos, maximum):
+def parseLinkDestination(string: str, pos: int, maximum: int) -> _Result:
     lines = 0
     start = pos
     result = _Result()
diff --git a/markdown_it/helpers/parse_link_label.py b/markdown_it/helpers/parse_link_label.py
index b0e4f0f1..20e3c148 100644
--- a/markdown_it/helpers/parse_link_label.py
+++ b/markdown_it/helpers/parse_link_label.py
@@ -5,9 +5,10 @@
 returns the end of the label
 
 """
+from markdown_it.rules_inline import StateInline
 
 
-def parseLinkLabel(state, start, disableNested=False):
+def parseLinkLabel(state: StateInline, start: int, disableNested: bool = False) -> int:
 
     labelEnd = -1
     oldPos = state.pos
diff --git a/markdown_it/helpers/parse_link_title.py b/markdown_it/helpers/parse_link_title.py
index 69f9aa87..048b4e60 100644
--- a/markdown_it/helpers/parse_link_title.py
+++ b/markdown_it/helpers/parse_link_title.py
@@ -16,7 +16,7 @@ def __str__(self):
         return self.str
 
 
-def parseLinkTitle(string, pos, maximum):
+def parseLinkTitle(string: str, pos: int, maximum: int) -> _Result:
     lines = 0
     start = pos
     result = _Result()
diff --git a/markdown_it/rules_block/state_block.py b/markdown_it/rules_block/state_block.py
index 0b29d8a8..01c32d9e 100644
--- a/markdown_it/rules_block/state_block.py
+++ b/markdown_it/rules_block/state_block.py
@@ -117,7 +117,7 @@ def __repr__(self):
             f"(line={self.line},level={self.level},tokens={len(self.tokens)})"
         )
 
-    def push(self, ttype, tag, nesting):
+    def push(self, ttype: str, tag: str, nesting: int) -> Token:
         """Push new token to "stream"."""
         token = Token(ttype, tag, nesting)
         token.block = True
@@ -129,7 +129,7 @@ def push(self, ttype, tag, nesting):
         self.tokens.append(token)
         return token
 
-    def isEmpty(self, line):
+    def isEmpty(self, line: int) -> bool:
         """."""
         return (self.bMarks[line] + self.tShift[line]) >= self.eMarks[line]
 
@@ -183,7 +183,7 @@ def skipCharsBack(self, pos: int, code: int, minimum: int) -> int:
                 return pos + 1
         return pos
 
-    def getLines(self, begin: int, end: int, indent, keepLastLF):
+    def getLines(self, begin: int, end: int, indent: int, keepLastLF: bool) -> str:
         """Cut lines range from source."""
         line = begin
         if begin >= end:
diff --git a/markdown_it/rules_core/block.py b/markdown_it/rules_core/block.py
index b47a5d8f..fa1c52c4 100644
--- a/markdown_it/rules_core/block.py
+++ b/markdown_it/rules_core/block.py
@@ -2,7 +2,7 @@
 from .state_core import StateCore
 
 
-def block(state: StateCore):
+def block(state: StateCore) -> None:
 
     if state.inlineMode:
         token = Token("inline", "", 0)
diff --git a/markdown_it/rules_core/inline.py b/markdown_it/rules_core/inline.py
index 232d145a..32a95ada 100644
--- a/markdown_it/rules_core/inline.py
+++ b/markdown_it/rules_core/inline.py
@@ -1,7 +1,7 @@
 from .state_core import StateCore
 
 
-def inline(state: StateCore):
+def inline(state: StateCore) -> None:
     """Parse inlines"""
     for token in state.tokens:
         if token.type == "inline":
diff --git a/markdown_it/rules_core/linkify.py b/markdown_it/rules_core/linkify.py
index 83091d36..eac7aa65 100644
--- a/markdown_it/rules_core/linkify.py
+++ b/markdown_it/rules_core/linkify.py
@@ -14,15 +14,15 @@
 TEST_MAILTO_RE = re.compile(r"^mailto:", flags=re.IGNORECASE)
 
 
-def isLinkOpen(string: str):
-    return LINK_OPEN_RE.search(string)
+def isLinkOpen(string: str) -> bool:
+    return bool(LINK_OPEN_RE.search(string))
 
 
-def isLinkClose(string: str):
-    return LINK_CLOSE_RE.search(string)
+def isLinkClose(string: str) -> bool:
+    return bool(LINK_CLOSE_RE.search(string))
 
 
-def linkify(state: StateCore):
+def linkify(state: StateCore) -> None:
     blockTokens = state.tokens
 
     if not state.md.options.linkify:
diff --git a/markdown_it/rules_core/normalize.py b/markdown_it/rules_core/normalize.py
index 35e7a1c1..14b2f679 100644
--- a/markdown_it/rules_core/normalize.py
+++ b/markdown_it/rules_core/normalize.py
@@ -9,7 +9,7 @@
 NULL_RE = re.compile(r"\0")
 
 
-def normalize(state: StateCore):
+def normalize(state: StateCore) -> None:
 
     # Normalize newlines
     string = NEWLINES_RE.sub("\n", state.src)
diff --git a/markdown_it/rules_core/replacements.py b/markdown_it/rules_core/replacements.py
index 5a135277..ee3b9edb 100644
--- a/markdown_it/rules_core/replacements.py
+++ b/markdown_it/rules_core/replacements.py
@@ -59,7 +59,7 @@ def replaceFn(match: Match[str]):
     return SCOPED_ABBR[match.group(1).lower()]
 
 
-def replace_scoped(inlineTokens: List[Token]):
+def replace_scoped(inlineTokens: List[Token]) -> None:
     inside_autolink = 0
 
     for token in inlineTokens:
@@ -73,7 +73,7 @@ def replace_scoped(inlineTokens: List[Token]):
             inside_autolink += 1
 
 
-def replace_rare(inlineTokens: List[Token]):
+def replace_rare(inlineTokens: List[Token]) -> None:
     inside_autolink = 0
 
     for token in inlineTokens:
@@ -108,7 +108,7 @@ def replace_rare(inlineTokens: List[Token]):
             inside_autolink += 1
 
 
-def replace(state: StateCore):
+def replace(state: StateCore) -> None:
     if not state.md.options.typographer:
         return
 
diff --git a/markdown_it/rules_core/smartquotes.py b/markdown_it/rules_core/smartquotes.py
index 3b25d30c..c3211191 100644
--- a/markdown_it/rules_core/smartquotes.py
+++ b/markdown_it/rules_core/smartquotes.py
@@ -14,14 +14,14 @@
 APOSTROPHE = "\u2019"  # ’
 
 
-def replaceAt(string: str, index: int, ch: str):
+def replaceAt(string: str, index: int, ch: str) -> str:
     # When the index is negative, the behavior is different from the js version.
     # But basically, the index will not be negative.
     assert index >= 0
     return string[:index] + ch + string[index + 1 :]
 
 
-def process_inlines(tokens: List[Token], state: StateCore):
+def process_inlines(tokens: List[Token], state: StateCore) -> None:
     stack: List[Dict[str, Any]] = []
 
     for i in range(len(tokens)):
@@ -190,7 +190,7 @@ def process_inlines(tokens: List[Token], state: StateCore):
                 )
 
 
-def smartquotes(state: StateCore):
+def smartquotes(state: StateCore) -> None:
     if not state.md.options.typographer:
         return
 
diff --git a/markdown_it/rules_inline/autolink.py b/markdown_it/rules_inline/autolink.py
index 59444092..b07396e2 100644
--- a/markdown_it/rules_inline/autolink.py
+++ b/markdown_it/rules_inline/autolink.py
@@ -9,7 +9,7 @@
 AUTOLINK_RE = re.compile(r"^<([a-zA-Z][a-zA-Z0-9+.\-]{1,31}):([^<>\x00-\x20]*)>")
 
 
-def autolink(state: StateInline, silent: bool):
+def autolink(state: StateInline, silent: bool) -> bool:
 
     pos = state.pos
 
diff --git a/markdown_it/rules_inline/backticks.py b/markdown_it/rules_inline/backticks.py
index b843c94e..67e41c73 100644
--- a/markdown_it/rules_inline/backticks.py
+++ b/markdown_it/rules_inline/backticks.py
@@ -6,7 +6,7 @@
 regex = re.compile("^ (.+) $")
 
 
-def backtick(state: StateInline, silent: bool):
+def backtick(state: StateInline, silent: bool) -> bool:
 
     pos = state.pos
     ch = state.srcCharCode[pos]
diff --git a/markdown_it/rules_inline/balance_pairs.py b/markdown_it/rules_inline/balance_pairs.py
index 643461b2..deff41e6 100644
--- a/markdown_it/rules_inline/balance_pairs.py
+++ b/markdown_it/rules_inline/balance_pairs.py
@@ -91,7 +91,7 @@ def processDelimiters(state: StateInline, delimiters, *args):
         closerIdx += 1
 
 
-def link_pairs(state: StateInline):
+def link_pairs(state: StateInline) -> None:
     tokens_meta = state.tokens_meta
     maximum = len(state.tokens_meta)