Valuation stocks and preferred stock?

Yes if there is a clause while issuing common stock that stock holder can convert the common stock to preffered stock.

pay dividend before common stock

stock (a flavoured liquid prepared by simmering various ingredients in water) that has the attribute favourite (most preferred)

The phrase 'preferred stock' means stock whose holders are guaranteed priority in the payment of dividends but whose holders have no voting rights

Common stocks--a type of stock that pays a variable dividend and gives the holder voting rights.Preferred stocks--a type of stock that pays a fixed dividend and carries no voting rights.