diff --git a/minitorch/module.py b/minitorch/module.py
index 8f17cfb..78e391d 100644
--- a/minitorch/module.py
+++ b/minitorch/module.py
@@ -31,13 +31,24 @@ def modules(self) -> Sequence[Module]:
 
     def train(self) -> None:
         "Set the mode of this module and all descendent modules to `train`."
-        # TODO: Implement for Task 0.4.
-        raise NotImplementedError("Need to implement for Task 0.4")
+        self._set_mode(self, train=True)
+
+    def _set_mode(self, root: Module, train: bool = False) -> None:
+        if not root:
+            return
+
+        if train:
+            root.training = True
+        else:
+            root.training = False
+        modules = getattr(root, "_modules", None)
+        if modules is not None:
+            for _, v in modules.items():
+                self._set_mode(v, train)
 
     def eval(self) -> None:
         "Set the mode of this module and all descendent modules to `eval`."
-        # TODO: Implement for Task 0.4.
-        raise NotImplementedError("Need to implement for Task 0.4")
+        self._set_mode(self, train=False)
 
     def named_parameters(self) -> Sequence[Tuple[str, Parameter]]:
         """
@@ -47,13 +58,33 @@ def named_parameters(self) -> Sequence[Tuple[str, Parameter]]:
         Returns:
             The name and `Parameter` of each ancestor parameter.
         """
-        # TODO: Implement for Task 0.4.
-        raise NotImplementedError("Need to implement for Task 0.4")
+        return self._traverse_tree(self, named=True)
+
+    def _traverse_tree(
+        self, root: Module, named: bool = False, path: str = ""
+    ) -> Sequence[Tuple[str, Parameter] | Parameter]:
+        result = []
+        if not root:
+            return result
+
+        parameters = getattr(root, "_parameters", None)
+        if parameters is not None:
+            for k, p in parameters.items():
+                if named:
+                    result.append((f"{path}.{k}" if path else f"{k}", p))
+                else:
+                    result.append(p)
+        modules = getattr(root, "_modules", None)
+        if modules is not None:
+            for name, v in modules.items():
+                path_sofar = f"{path}.{name}" if path else name
+                result.extend(self._traverse_tree(v, named=named, path=path_sofar))
+
+        return result
 
     def parameters(self) -> Sequence[Parameter]:
         "Enumerate over all the parameters of this module and its descendents."
-        # TODO: Implement for Task 0.4.
-        raise NotImplementedError("Need to implement for Task 0.4")
+        return self._traverse_tree(self)
 
     def add_parameter(self, k: str, v: Any) -> Parameter:
         """