diff --git a/tool-testsuite/test/org/antlr/v4/test/tool/TestSymbolIssues.java b/tool-testsuite/test/org/antlr/v4/test/tool/TestSymbolIssues.java
index 710da08b4..1c68ba30a 100644
--- a/tool-testsuite/test/org/antlr/v4/test/tool/TestSymbolIssues.java
+++ b/tool-testsuite/test/org/antlr/v4/test/tool/TestSymbolIssues.java
@@ -198,9 +198,9 @@ public class TestSymbolIssues extends BaseTest {
 			"C: 'c';",
 
 			"error(" + ErrorType.RESERVED_RULE_NAME.code + "): L.g4:5:0: cannot declare a rule with reserved name MIN_CHAR_VALUE\n" +
-			"error(" + ErrorType.MODE_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:4:0: can not use or declare mode with reserved name MAX_CHAR_VALUE\n" +
-			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:11: can not use or declare channel with reserved name SKIP\n" +
-			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:17: can not use or declare channel with reserved name HIDDEN\n"
+			"error(" + ErrorType.MODE_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:4:0: cannot use or declare mode with reserved name MAX_CHAR_VALUE\n" +
+			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:11: cannot use or declare channel with reserved name SKIP\n" +
+			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:17: cannot use or declare channel with reserved name HIDDEN\n"
 		};
 
 		testErrors(test, false);
@@ -216,9 +216,9 @@ public class TestSymbolIssues extends BaseTest {
 			"E: 'e' -> type(EOF);\n" +
 			"F: 'f' -> pushMode(DEFAULT_MODE);",
 
-			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:18: can not use or declare channel with reserved name SKIP\n" +
-			"error(" + ErrorType.TOKEN_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:3:15: can not use or declare token with reserved name MORE\n" +
-			"error(" + ErrorType.MODE_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:4:15: can not use or declare mode with reserved name SKIP\n"
+			"error(" + ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:2:18: cannot use or declare channel with reserved name SKIP\n" +
+			"error(" + ErrorType.TOKEN_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:3:15: cannot use or declare token with reserved name MORE\n" +
+			"error(" + ErrorType.MODE_CONFLICTS_WITH_COMMON_CONSTANTS.code + "): L.g4:4:15: cannot use or declare mode with reserved name SKIP\n"
 		};
 
 		testErrors(test, false);
diff --git a/tool-testsuite/test/org/antlr/v4/test/tool/TestToolSyntaxErrors.java b/tool-testsuite/test/org/antlr/v4/test/tool/TestToolSyntaxErrors.java
index f27baa87e..c41143422 100644
--- a/tool-testsuite/test/org/antlr/v4/test/tool/TestToolSyntaxErrors.java
+++ b/tool-testsuite/test/org/antlr/v4/test/tool/TestToolSyntaxErrors.java
@@ -467,11 +467,11 @@ public class TestToolSyntaxErrors extends BaseTest {
 			"Error3: '';\n" +
 			"NotError: ' ';";
 		String expected =
-			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:2:8: empty strings not allowed\n" +
-			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:2:16: empty strings not allowed\n" +
-			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:3:8: empty strings not allowed\n" +
-			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:4:15: empty strings not allowed\n" +
-			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:5:8: empty strings not allowed\n";
+			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:2:8: string literals cannot be empty\n" +
+			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:2:16: string literals cannot be empty\n" +
+			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:3:8: string literals cannot be empty\n" +
+			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:4:15: string literals cannot be empty\n" +
+			"error(" + ErrorType.EMPTY_STRINGS_NOT_ALLOWED.code + "): T.g4:5:8: string literals cannot be empty\n";
 
 		String[] pair = new String[] {
 				grammar,
diff --git a/tool/src/org/antlr/v4/automata/LexerATNFactory.java b/tool/src/org/antlr/v4/automata/LexerATNFactory.java
index a1dcaf669..a5e80e47d 100644
--- a/tool/src/org/antlr/v4/automata/LexerATNFactory.java
+++ b/tool/src/org/antlr/v4/automata/LexerATNFactory.java
@@ -83,7 +83,7 @@ public class LexerATNFactory extends ParserATNFactory {
 	 * actions, but are required during code generation for creating
 	 * {@link LexerAction} instances that are usable by a lexer interpreter.
 	 */
-	protected static final Map<String, Integer> COMMON_CONSTANTS = new HashMap<String, Integer>();
+	public static final Map<String, Integer> COMMON_CONSTANTS = new HashMap<String, Integer>();
 	static {
 		COMMON_CONSTANTS.put("HIDDEN", Lexer.HIDDEN);
 		COMMON_CONSTANTS.put("DEFAULT_TOKEN_CHANNEL", Lexer.DEFAULT_TOKEN_CHANNEL);
diff --git a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
index 73fd95ed1..ada4324ba 100644
--- a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
+++ b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
@@ -69,11 +69,6 @@ import java.util.Set;
  *  tokens and rules from the imported grammars into a single collection.
  */
 public class SemanticPipeline {
-	protected final Set<String> reservedNames = new HashSet<String>();
-	{
-		reservedNames.addAll(LexerATNFactory.getCommonConstants());
-	}
-
 	public Grammar g;
 
 	public SemanticPipeline(Grammar g) {
@@ -295,7 +290,7 @@ public class SemanticPipeline {
 				g.tool.errMgr.grammarError(ErrorType.CHANNEL_CONFLICTS_WITH_TOKEN, g.fileName, channel.token, channelName);
 			}
 
-			if (reservedNames.contains(channelName)) {
+			if (LexerATNFactory.COMMON_CONSTANTS.containsKey(channelName)) {
 				g.tool.errMgr.grammarError(ErrorType.CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS, g.fileName, channel.token, channelName);
 			}
 
diff --git a/tool/src/org/antlr/v4/tool/ErrorType.java b/tool/src/org/antlr/v4/tool/ErrorType.java
index c733e07c8..0fedfc4a9 100644
--- a/tool/src/org/antlr/v4/tool/ErrorType.java
+++ b/tool/src/org/antlr/v4/tool/ErrorType.java
@@ -978,9 +978,9 @@ public enum ErrorType {
 	 *
 	 * <p>Reserved names: HIDDEN, DEFAULT_TOKEN_CHANNEL, SKIP, MORE, MAX_CHAR_VALUE, MIN_CHAR_VALUE.
 	 *
-	 * <p>Can be used but can not be declared: EOF</p>
+	 * <p>Can be used but cannot be declared: EOF</p>
 	 */
-	TOKEN_CONFLICTS_WITH_COMMON_CONSTANTS(171, "can not use or declare token with reserved name <arg>", ErrorSeverity.ERROR),
+	TOKEN_CONFLICTS_WITH_COMMON_CONSTANTS(171, "cannot use or declare token with reserved name <arg>", ErrorSeverity.ERROR),
 	/**
 	 * Compiler Error 172.
 	 *
@@ -988,9 +988,9 @@ public enum ErrorType {
 	 *
 	 * <p>Reserved names: DEFAULT_MODE, SKIP, MORE, EOF, MAX_CHAR_VALUE, MIN_CHAR_VALUE.
 	 *
-	 * <p>Can be used but can not be declared: HIDDEN, DEFAULT_TOKEN_CHANNEL</p>
+	 * <p>Can be used but cannot be declared: HIDDEN, DEFAULT_TOKEN_CHANNEL</p>
 	 */
-	CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS(172, "can not use or declare channel with reserved name <arg>", ErrorSeverity.ERROR),
+	CHANNEL_CONFLICTS_WITH_COMMON_CONSTANTS(172, "cannot use or declare channel with reserved name <arg>", ErrorSeverity.ERROR),
 	/**
 	 * Compiler Error 173.
 	 *
@@ -998,9 +998,9 @@ public enum ErrorType {
 	 *
 	 * <p>Reserved names: HIDDEN, DEFAULT_TOKEN_CHANNEL, SKIP, MORE, MAX_CHAR_VALUE, MIN_CHAR_VALUE.
 	 *
-	 * <p>Can be used and can be declared: DEFAULT_MODE</p>
+	 * <p>Can be used and cannot declared: DEFAULT_MODE</p>
 	 */
-	MODE_CONFLICTS_WITH_COMMON_CONSTANTS(173, "can not use or declare mode with reserved name <arg>", ErrorSeverity.ERROR),
+	MODE_CONFLICTS_WITH_COMMON_CONSTANTS(173, "cannot use or declare mode with reserved name <arg>", ErrorSeverity.ERROR),
 	/**
 	 * Compiler Error 174.
 	 *
@@ -1010,7 +1010,7 @@ public enum ErrorType {
 	 * <pre>B: '';</pre>
 	 * <pre>C: 'test' '';</pre>
 	 */
-	EMPTY_STRINGS_NOT_ALLOWED(174, "empty strings not allowed", ErrorSeverity.ERROR),
+	EMPTY_STRINGS_NOT_ALLOWED(174, "string literals cannot be empty", ErrorSeverity.ERROR),
 
 	/*
 	 * Backward incompatibility errors