#_form.html.erb
<%= form_for([@user , @user.newss.build]) do |form| %>
  <%# if news.errors.any? %>
    <div id="error_explanation">
      <h2><%#= pluralize(news.errors.count, "error") %> prohibited this
news from being saved:</h2>

      <ul>
      <%# news.errors.full_messages.each do |message| %>
        <li><%#= message %></li>
      <%# end %>
      </ul>
    </div>
   <%# end %>

  <div class="field">
    <%= form.label :title %>
    <%= form.text_field :title %>
  </div>

  <div class="field">
    <%= form.label :description %>
    <%= form.text_area :description %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>

#my user.rb
class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable
  has_many :news
end
#my news.rb
class News < ApplicationRecord
    has_many :comments
    belongs_to :user
end


##it shows different kind of errors I can't understand that...##