I would guess at least 80% of common SQL and T-SQL from Sybase is still completely compatible with SQL Server. As a side note, I had no idea Sybase still exist

I would guess at least 80% of common SQL and T-SQL from Sybase is still completely compatible with SQL Server. As a side note, I had no idea Sybase still existed at all. Looks like it's now part of SAP's portfolio.