As a user I want to be able to provide Forms and Senses of a Lexeme. I want to be able to make Statements (including References and Qualifiers) about the different Forms and Senses of a Lexeme. I also want to be able to make Statements about the Lexeme itself in order to record the etymology of a word for example. The existing Items and Properties can be used to make such Statements. Adding, editing, removing should work like they do for items.
As a user, I also want to be able to reference individual Forms and Senses from Statements, in the same way I can reference Items and Properties.
Forms and Senses shall be stored as part of the same page as the Lexeme they belong to, and thus share that page's history, talk page, protection status, etc.