diff --git a/DevTips/DevTips/Program.cs b/DevTips/DevTips/Program.cs
index 9f4bdaf..b335e67 100644
--- a/DevTips/DevTips/Program.cs
+++ b/DevTips/DevTips/Program.cs
@@ -17,6 +17,9 @@ class Program
         // ActionClient.Client();
 
         // Func
-        FuncClient.Client();
+        // FuncClient.Client();
+
+        // Predicate
+        PreicateClient.Client();
     }
 }
diff --git a/DevTips/DevTips/Tips/ActionClient.cs b/DevTips/DevTips/Tips/ActionClient.cs
index 8be16ef..83b3236 100644
--- a/DevTips/DevTips/Tips/ActionClient.cs
+++ b/DevTips/DevTips/Tips/ActionClient.cs
@@ -1,3 +1,5 @@
+using System;
+
 namespace DevTips.Tips
 {
     class ActionClient
diff --git a/DevTips/DevTips/Tips/FuncClient.cs b/DevTips/DevTips/Tips/FuncClient.cs
index d8fc650..c32a097 100644
--- a/DevTips/DevTips/Tips/FuncClient.cs
+++ b/DevTips/DevTips/Tips/FuncClient.cs
@@ -1,3 +1,5 @@
+using System;
+
 namespace DevTips.Tips
 {
     class FuncClient
diff --git a/DevTips/DevTips/Tips/LinqGroupMinMax.cs b/DevTips/DevTips/Tips/LinqGroupMinMax.cs
index 013bab2..15ff667 100644
--- a/DevTips/DevTips/Tips/LinqGroupMinMax.cs
+++ b/DevTips/DevTips/Tips/LinqGroupMinMax.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Data;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/DevTips/DevTips/Tips/PreicateClient.cs b/DevTips/DevTips/Tips/PreicateClient.cs
new file mode 100644
index 0000000..510d3ce
--- /dev/null
+++ b/DevTips/DevTips/Tips/PreicateClient.cs
@@ -0,0 +1,18 @@
+using System;
+
+namespace DevTips.Tips;
+
+class PreicateClient
+{
+    public static void Client()
+    {
+        Predicate<int> p = delegate(int n)
+        {
+            return n >= 0;
+        };
+        System.Console.WriteLine($"p(-1): {p(-1)}");
+
+        Predicate<string> p2 = s => s.StartsWith("A");
+        System.Console.WriteLine($"p2(\"Apple\"): {p2("Apple")}");
+    }
+}
\ No newline at end of file