diff --git a/utils/tree_sitter/README.md b/utils/tree_sitter/README.md
index b15984e9f262..f37a2422f238 100644
--- a/utils/tree_sitter/README.md
+++ b/utils/tree_sitter/README.md
@@ -17,6 +17,27 @@ To install tree-sitter, run:
 npm install -g tree-sitter-cli
 ```
 
+### Building and Testing
+
+To build and test changes to the grammar using Bazel, provide specific flags to
+allow the build to access the system `tree-sitter` binary and environment.
+
+```bash
+bazel test //utils/tree_sitter:string_tests \
+  --strategy=Genrule=local \
+  --action_env=PATH \
+  --action_env=HOME
+```
+
+-   `--strategy=Genrule=local`: Disables sandboxing for the genrule that runs
+    `tree-sitter generate`, allowing it to find the system-installed binary.
+-   `--action_env=PATH`: Passes your current `PATH` to the build actions,
+    ensuring `tree-sitter` can be found. If `tree-sitter` is not in your default
+    PATH, you can specify it explicitly, for example:
+    `--action_env=PATH=/path/to/tree-sitter/bin:$PATH`.
+-   `--action_env=HOME`: Passes your `HOME` environment variable, which
+    `tree-sitter` may need to locate its configuration or cache.
+
 ## Editor Installation
 
 ### Helix
diff --git a/utils/tree_sitter/grammar.js b/utils/tree_sitter/grammar.js
index da8f2ef7a9a8..155a289ce566 100644
--- a/utils/tree_sitter/grammar.js
+++ b/utils/tree_sitter/grammar.js
@@ -46,6 +46,7 @@ module.exports = grammar({
   conflicts: ($) => [
     [$.paren_pattern, $.paren_expression],
     [$.struct_literal, $.struct_type_literal],
+    [$._pattern_without_expression, $._simple_expression],
   ],
 
   extras: ($) => [/\s/, $.comment],
@@ -163,6 +164,7 @@ module.exports = grammar({
     _pattern_without_expression: ($) =>
       choice(
         'auto',
+        seq(optional('ref'), 'self', optional(seq(':', $._expression))),
         seq($.binding_lhs, ':', $._expression),
         seq($.binding_lhs, ':!', $._expression),
         seq('template', $.binding_lhs, ':!', $._expression),
@@ -316,7 +318,7 @@ module.exports = grammar({
 
     var_declaration: ($) =>
       seq(
-        'var',
+        seq(optional('static'), 'var'),
         $._pattern_without_expression,
         optional(seq('=', $._expression)),
         ';'
@@ -379,11 +381,7 @@ module.exports = grammar({
     generic_binding: ($) =>
       seq(optional('template'), $.ident, ':!', $._expression),
 
-    deduced_param: ($) =>
-      choice(
-        $.generic_binding,
-        seq(optional('addr'), 'self', ':', $._expression)
-      ),
+    deduced_param: ($) => $.generic_binding,
 
     deduced_params: ($) => seq('[', comma_sep($.deduced_param), ']'),
 
diff --git a/utils/tree_sitter/testdata/string/self_parameter.carbon b/utils/tree_sitter/testdata/string/self_parameter.carbon
new file mode 100644
index 000000000000..19a44548e652
--- /dev/null
+++ b/utils/tree_sitter/testdata/string/self_parameter.carbon
@@ -0,0 +1,11 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+class Point {
+  var x: i32;
+
+  fn GetX(self: Point) -> i32 { return self.x; }
+  fn GetY(self) -> i32 { return 0; }
+  fn SetX(ref self, new_x: i32) {}
+}
diff --git a/utils/tree_sitter/testdata/string/static_var.carbon b/utils/tree_sitter/testdata/string/static_var.carbon
new file mode 100644
index 000000000000..f523a7ddda54
--- /dev/null
+++ b/utils/tree_sitter/testdata/string/static_var.carbon
@@ -0,0 +1,7 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+class Widget {
+  static var count: i32;
+}