diff --git a/bin/Lng/Eng/SemanticErrors_ib.dat b/bin/Lng/Eng/SemanticErrors_ib.dat
index 32b8e8c45..795653dbf 100644
--- a/bin/Lng/Eng/SemanticErrors_ib.dat
+++ b/bin/Lng/Eng/SemanticErrors_ib.dat
@@ -94,6 +94,11 @@ ONLY_CLASS_CAN_BE_PARTIAL=partial is applicable to classes only
 OPERATORS_SHOULD_HAVE_{0}_PARAMETERS={0} parameter(s) expected
 OPERATORS_SHOULD_HAVE_1_OR_2_PARAMETERS=1 or 2 parameters expected
 LEAST_ONE_PARAMETER_TYPE_SHOULD_EQ_DECLARING_TYPE_{0}=At least one parameter should have type {0}
+EXTENSION_ATTRIBUTE_ONLY_FOR_NAMESPACE_FUNCTIONS_ALLOWED=extensionmethod attribute can be applied only to global functions
+EXTENSION_METHODS_MUST_HAVE_LEAST_ONE_PARAMETER=Parameter with name 'self' expected
+FIRST_PARAMETER_SHOULDBE_ONLY_VALUE_PARAMETER=var and const are not allowed for first parameter of extension method
+FIRST_PARAMETER_MUST_HAVE_NAME_SELF=Parameter with 'name' self expected
+EXTENSION_METHODS_FOR_CONSTRUCTED_TYPES_NOT_ALLOWED=Cannot extend this type
 %PREFIX%=COMPILATIONERROR_
 UNIT_MODULE_EXPECTED_LIBRARY_FOUND=Unit expected, library found
 ASSEMBLY_{0}_READING_ERROR=Error by reading assembly '{0}'