In 2007 I started a business as a single member Limited Liability Company. In 2010 I added a partner resulting in a partnership for federal income tax purposes. It was discovered then that I had failed to capitalize a lease and depreciate it 2007, 2008, and 2009: I had instead just expensed the lease as an operating lease. How do I correct this error? Do I amend my 2009 Form 1040 with a Form 3115 since the partnership formed in 2010 may be a new taxpayer?