Grasses often take a good bit of work looking at very small structures, some of which you only have access to when they’re blooming or in seed.
Here is a very basic overview of the sorts of things you need to pay attention to when identifying grasses.
Here is a longer ID guide with photos to demonstrate real-world examples of what the structures looks like.
And another for common grasses in the US.
- https://www.kingsagriseeds.com/wp-content/uploads/2014/12/Penn-State-Grass-Identification-Matrix.pdf
Some native forage grasses in the southern states.
One on pasture grasses.