|Introduction to Sumerian Grammar||An older text, but still very helpful.|
|Sumerian Language||A brief introduction with some grammar topics.|
|The Origin of the Sumerian Language||Not so much grammar, but still useful for placing the language in the proper context.|
|Learn Sumerian Grammar||A collection of lessons from Wikibooks. Check it out!|
|Memrise Sumerian Course||It's an online course for learning Sumerian; you'll have to create an account, though.|
Recommendations coming soon!