diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 36aef619888..fd0e42e60bf 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -63,7 +63,7 @@ namespace ts {
         {
             name: "reactNamespace",
             type: "string",
-            description: Diagnostics.Specifies_the_object_invoked_for_createElement_and_spread_when_targeting_react_JSX_emit
+            description: Diagnostics.Specify_the_object_invoked_for_createElement_and_spread_when_targeting_react_JSX_emit
         },
         {
             name: "listFiles",
@@ -77,7 +77,7 @@ namespace ts {
             name: "mapRoot",
             type: "string",
             isFilePath: true,
-            description: Diagnostics.Specifies_the_location_where_debugger_should_locate_map_files_instead_of_generated_locations,
+            description: Diagnostics.Specify_the_location_where_debugger_should_locate_map_files_instead_of_generated_locations,
             paramType: Diagnostics.LOCATION,
         },
         {
@@ -102,7 +102,7 @@ namespace ts {
                 "crlf": NewLineKind.CarriageReturnLineFeed,
                 "lf": NewLineKind.LineFeed
             },
-            description: Diagnostics.Specifies_the_end_of_line_sequence_to_be_used_when_emitting_files_Colon_CRLF_dos_or_LF_unix,
+            description: Diagnostics.Specify_the_end_of_line_sequence_to_be_used_when_emitting_files_Colon_CRLF_dos_or_LF_unix,
             paramType: Diagnostics.NEWLINE,
             error: Diagnostics.Argument_for_newLine_option_must_be_CRLF_or_LF
         },
@@ -187,7 +187,7 @@ namespace ts {
             type: "string",
             isFilePath: true,
             paramType: Diagnostics.LOCATION,
-            description: Diagnostics.Specifies_the_root_directory_of_input_files_Use_to_control_the_output_directory_structure_with_outDir,
+            description: Diagnostics.Specify_the_root_directory_of_input_files_Use_to_control_the_output_directory_structure_with_outDir,
         },
         {
             name: "isolatedModules",
@@ -202,7 +202,7 @@ namespace ts {
             name: "sourceRoot",
             type: "string",
             isFilePath: true,
-            description: Diagnostics.Specifies_the_location_where_debugger_should_locate_TypeScript_files_instead_of_source_locations,
+            description: Diagnostics.Specify_the_location_where_debugger_should_locate_TypeScript_files_instead_of_source_locations,
             paramType: Diagnostics.LOCATION,
         },
         {
@@ -231,7 +231,7 @@ namespace ts {
                 "es6": ScriptTarget.ES6,
                 "es2015": ScriptTarget.ES2015,
             },
-            description: Diagnostics.Specify_ECMAScript_target_version_Colon_ES3_default_ES5_or_ES2015_experimental,
+            description: Diagnostics.Specify_ECMAScript_target_version_Colon_ES3_default_ES5_or_ES2015,
             paramType: Diagnostics.VERSION,
             error: Diagnostics.Argument_for_target_option_must_be_ES3_ES5_or_ES2015
         },
@@ -264,7 +264,7 @@ namespace ts {
                 "node": ModuleResolutionKind.NodeJs,
                 "classic": ModuleResolutionKind.Classic,
             },
-            description: Diagnostics.Specifies_module_resolution_strategy_Colon_node_Node_js_or_classic_TypeScript_pre_1_6,
+            description: Diagnostics.Specify_module_resolution_strategy_Colon_node_Node_js_or_classic_TypeScript_pre_1_6,
             error: Diagnostics.Argument_for_moduleResolution_option_must_be_node_or_classic,
         },
         {
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 15a3a4e5ef4..a264285d95f 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -2240,11 +2240,11 @@
         "category": "Message",
         "code": 6002
     },
-    "Specifies the location where debugger should locate map files instead of generated locations.": {
+    "Specify the location where debugger should locate map files instead of generated locations.": {
         "category": "Message",
         "code": 6003
     },
-    "Specifies the location where debugger should locate TypeScript files instead of source locations.": {
+    "Specify the location where debugger should locate TypeScript files instead of source locations.": {
         "category": "Message",
         "code": 6004
     },
@@ -2276,7 +2276,7 @@
         "category": "Message",
         "code": 6011
     },
-    "Specify ECMAScript target version: 'ES3' (default), 'ES5', or 'ES2015' (experimental)": {
+    "Specify ECMAScript target version: 'ES3' (default), 'ES5', or 'ES2015'": {
         "category": "Message",
         "code": 6015
     },
@@ -2408,7 +2408,7 @@
         "category": "Message",
         "code": 6056
     },
-    "Specifies the root directory of input files. Use to control the output directory structure with --outDir.": {
+    "Specify the root directory of input files. Use to control the output directory structure with --outDir.": {
         "category": "Message",
         "code": 6058
     },
@@ -2416,7 +2416,7 @@
         "category": "Error",
         "code": 6059
     },
-    "Specifies the end of line sequence to be used when emitting files: 'CRLF' (dos) or 'LF' (unix).": {
+    "Specify the end of line sequence to be used when emitting files: 'CRLF' (dos) or 'LF' (unix).": {
         "category": "Message",
         "code": 6060
     },
@@ -2448,7 +2448,7 @@
         "category": "Message",
         "code": 6068
     },
-    "Specifies module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6).": {
+    "Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6).": {
         "category": "Message",
         "code": 6069
     },
@@ -2504,7 +2504,7 @@
         "category": "Message",
         "code": 6083
     },
-    "Specifies the object invoked for createElement and __spread when targeting 'react' JSX emit": {
+    "Specify the object invoked for createElement and __spread when targeting 'react' JSX emit": {
         "category": "Message",
         "code": 6084
     },