diff --git a/src/Playwright.Tests/Locator/LocatorQueryTests.cs b/src/Playwright.Tests/Locator/LocatorQueryTests.cs
new file mode 100644
index 0000000000..af0996f77c
--- /dev/null
+++ b/src/Playwright.Tests/Locator/LocatorQueryTests.cs
@@ -0,0 +1,85 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System.Threading.Tasks;
+using NUnit.Framework;
+
+namespace Microsoft.Playwright.Tests.Locator
+{
+    public class LocatorQueryTests : PageTestEx
+    {
+        [PlaywrightTest("locator-query.spec.ts", "should respect first() and last()")]
+        public async Task ShouldRespectFirstAndLast()
+        {
+            await Page.SetContentAsync(@"
+                <section>
+                    <div><p>A</p></div>
+                    <div><p>A</p><p>A</p></div>
+                    <div><p>A</p><p>A</p><p>A</p></div>
+                </section>");
+            Assert.AreEqual(6, await Page.Locator("div >> p").CountAsync());
+            Assert.AreEqual(6, await Page.Locator("div").Locator("p").CountAsync());
+            Assert.AreEqual(1, await Page.Locator("div").First.Locator("p").CountAsync());
+            Assert.AreEqual(3, await Page.Locator("div").Last.Locator("p").CountAsync());
+        }
+
+        [PlaywrightTest("locator-query.spec.ts", "should respect nth()")]
+        public async Task ShouldRespectNth()
+        {
+            await Page.SetContentAsync(@"
+                <section>
+                    <div><p>A</p></div>
+                    <div><p>A</p><p>A</p></div>
+                    <div><p>A</p><p>A</p><p>A</p></div>
+                </section>");
+            Assert.AreEqual(1, await Page.Locator("div >> p").Nth(0).CountAsync());
+            Assert.AreEqual(2, await Page.Locator("div").Nth(1).Locator("p").CountAsync());
+            Assert.AreEqual(3, await Page.Locator("div").Nth(2).Locator("p").CountAsync());
+        }
+
+        [PlaywrightTest("locator-query.spec.ts", "should throw on capture w/ nth()")]
+        public async Task ShouldThrowOnCaptureWithNth()
+        {
+            await Page.SetContentAsync("<section><div><p>A</p></div></section>");
+            var exception = await PlaywrightAssert.ThrowsAsync<PlaywrightException>(() => Page.Locator("*css=div >> p").Nth(1).ClickAsync());
+            StringAssert.Contains("Can't query n-th element", exception.Message);
+        }
+
+        [PlaywrightTest("locator-query.spec.ts", "should throw on due to strictness")]
+        public async Task ShouldThrowDueToStrictness()
+        {
+            await Page.SetContentAsync("<div>A</div><div>B</div>");
+            var exception = await PlaywrightAssert.ThrowsAsync<PlaywrightException>(() => Page.Locator("div").IsVisibleAsync());
+            StringAssert.Contains("strict mode violation", exception.Message);
+        }
+
+        [PlaywrightTest("locator-query.spec.ts", "should throw on due to strictness 2")]
+        public async Task ShouldThrowDueToStrictness2()
+        {
+            await Page.SetContentAsync("<select><option>One</option><option>Two</option></select>");
+            var exception = await PlaywrightAssert.ThrowsAsync<PlaywrightException>(() => Page.Locator("option").EvaluateAsync("() => {}"));
+            StringAssert.Contains("strict mode violation", exception.Message);
+        }
+    }
+}
diff --git a/src/Playwright/API/Supplements/ILocator.cs b/src/Playwright/API/Supplements/ILocator.cs
new file mode 100644
index 0000000000..0d57c2103e
--- /dev/null
+++ b/src/Playwright/API/Supplements/ILocator.cs
@@ -0,0 +1,34 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace Microsoft.Playwright
+{
+    public partial interface ILocator
+    {
+        Task<JsonElement?> EvaluateAsync(string expression, object arg = null, LocatorEvaluateOptions options = null);
+    }
+}
diff --git a/src/Playwright/Core/Locator.cs b/src/Playwright/Core/Locator.cs
index a7a4ed7237..9a8fa794a0 100644
--- a/src/Playwright/Core/Locator.cs
+++ b/src/Playwright/Core/Locator.cs
@@ -43,9 +43,9 @@ public Locator(Frame parent, string selector)
             _selector = selector;
         }
 
-        public ILocator First => new Locator(_frame, $"{_selector} >> _nth=first");
+        public ILocator First => new Locator(_frame, $"{_selector} >> nth=0");
 
-        public ILocator Last => new Locator(_frame, $"{_selector} >> _nth=last");
+        public ILocator Last => new Locator(_frame, $"{_selector} >> nth=-1");
 
         public async Task<IReadOnlyList<string>> AllInnerTextsAsync()
         {
@@ -121,6 +121,9 @@ public Task<IReadOnlyList<IElementHandle>> ElementHandlesAsync()
         public Task<T> EvaluateAllAsync<T>(string expression, object arg = null)
             => _frame.EvalOnSelectorAllAsync<T>(_selector, expression, arg);
 
+        public Task<JsonElement?> EvaluateAsync(string expression, object arg = null, LocatorEvaluateOptions options = null)
+            => EvaluateAsync<JsonElement?>(expression, arg, options);
+
         public Task<T> EvaluateAsync<T>(string expression, object arg = null, LocatorEvaluateOptions options = null)
             => _frame.EvalOnSelectorAsync<T>(_selector, expression, arg, ConvertOptions<FrameEvalOnSelectorOptions>(options));
 
@@ -167,7 +170,7 @@ public Task<bool> IsVisibleAsync(LocatorIsVisibleOptions options = null)
             => _frame.IsVisibleAsync(_selector, ConvertOptions<FrameIsVisibleOptions>(options));
 
         public ILocator Nth(int index)
-            => new Locator(_frame, $"{_selector} >> _nth=${index}");
+            => new Locator(_frame, $"{_selector} >> nth={index}");
 
         public Task PressAsync(string key, LocatorPressOptions options = null)
             => _frame.PressAsync(_selector, key, ConvertOptions<FramePressOptions>(options));