diff --git a/sqlglot/dialects/clickhouse.py b/sqlglot/dialects/clickhouse.py
index fdc56c0e9..ecbca72f2 100644
--- a/sqlglot/dialects/clickhouse.py
+++ b/sqlglot/dialects/clickhouse.py
@@ -627,15 +627,18 @@ def _parse_function(
             )
 
             if parts:
-                params = self._parse_func_params(func)
+                anon_func: exp.Anonymous = t.cast(exp.Anonymous, func)
+                params = self._parse_func_params(anon_func)
 
                 kwargs = {
-                    "this": func.this,
-                    "expressions": func.expressions,
+                    "this": anon_func.this,
+                    "expressions": anon_func.expressions,
                 }
                 if parts[1]:
                     kwargs["parts"] = parts
-                    exp_class = exp.CombinedParameterizedAgg if params else exp.CombinedAggFunc
+                    exp_class: t.Type[exp.Expression] = (
+                        exp.CombinedParameterizedAgg if params else exp.CombinedAggFunc
+                    )
                 else:
                     exp_class = exp.ParameterizedAgg if params else exp.AnonymousAggFunc
 
diff --git a/sqlglot/expressions.py b/sqlglot/expressions.py
index 8884635f1..699051e04 100644
--- a/sqlglot/expressions.py
+++ b/sqlglot/expressions.py
@@ -404,9 +404,9 @@ def depth(self) -> int:
     def iter_expressions(self, reverse: bool = False) -> t.Iterator[Expression]:
         """Yields the key and expression for all arguments, exploding list args."""
         # remove tuple when python 3.7 is deprecated
-        for vs in reversed(tuple(self.args.values())) if reverse else self.args.values():
+        for vs in reversed(tuple(self.args.values())) if reverse else self.args.values():  # type: ignore
             if type(vs) is list:
-                for v in reversed(vs) if reverse else vs:
+                for v in reversed(vs) if reverse else vs:  # type: ignore
                     if hasattr(v, "parent"):
                         yield v
             else:
diff --git a/sqlglot/optimizer/annotate_types.py b/sqlglot/optimizer/annotate_types.py
index d9b5ae150..052b74229 100644
--- a/sqlglot/optimizer/annotate_types.py
+++ b/sqlglot/optimizer/annotate_types.py
@@ -287,15 +287,18 @@ def _annotate_args(self, expression: E) -> E:
 
     def _maybe_coerce(
         self, type1: exp.DataType | exp.DataType.Type, type2: exp.DataType | exp.DataType.Type
-    ) -> exp.DataType:
+    ) -> exp.DataType.Type:
         type1_value = type1.this if isinstance(type1, exp.DataType) else type1
         type2_value = type2.this if isinstance(type2, exp.DataType) else type2
 
         # We propagate the UNKNOWN type upwards if found
         if exp.DataType.Type.UNKNOWN in (type1_value, type2_value):
-            return exp.DataType.build("unknown")
+            return exp.DataType.Type.UNKNOWN
 
-        return type2_value if type2_value in self.coerces_to.get(type1_value, {}) else type1_value
+        return t.cast(
+            exp.DataType.Type,
+            type2_value if type2_value in self.coerces_to.get(type1_value, {}) else type1_value,
+        )
 
     def _annotate_binary(self, expression: B) -> B:
         self._annotate_args(expression)
diff --git a/sqlglot/optimizer/qualify_columns.py b/sqlglot/optimizer/qualify_columns.py
index 5a4622e87..0fd4fc647 100644
--- a/sqlglot/optimizer/qualify_columns.py
+++ b/sqlglot/optimizer/qualify_columns.py
@@ -526,7 +526,7 @@ def _expand_stars(
 ) -> None:
     """Expand stars to lists of column selections"""
 
-    new_selections = []
+    new_selections: t.List[exp.Expression] = []
     except_columns: t.Dict[int, t.Set[str]] = {}
     replace_columns: t.Dict[int, t.Dict[str, exp.Alias]] = {}
     rename_columns: t.Dict[int, t.Dict[str, str]] = {}