title: Regular Expression issue with Fluent validation
body: <p>Probably very silly issue but looking for help on this . </p>
  
  <p>I am adding MVC Fluent validation rules to model property but for some reason one of the validation rule is failing. Added a regular expression to allow  english and spanish characters and  no numeric or special characters allowed except <strong>- and '</strong>.  For some reason when user enters more than one valid character  as input the error is still displayed. </p>
  
  <p>Error is still displayed when User Input is  <strong>aA</strong></p>
  
  <p>I am using this RegE <strong>@"^[a-zA-Z-']$")</strong>  to allow users to english and spanish characters and  no numeric or special characters allowed except - and '.</p>
  
  <p>Any help is appreciated.</p>
  
  <pre><code>  RuleFor(x =&gt; x.FirstName)              
   .NotEmpty().WithLocalizedMessage(ResourceAreas.Messages.Message_PersonalDetails_1001_firstname)
   .Length(1, 
       20).WithLocalizedMessage(ResourceAreas.Messages.Message_Onboarding_100006_maxlength) 
   .Matches(@"^[a-zA-Z-']$").WithLocalizedMessage(ResourceAreas.Messages.Message_Onboarding_PersonalDetails_100007_validname);
  </code></pre>