That's annual winter rye grass (or something like that). It will die when it gets hot, but it will be back next winter unless you put out a pre-emergent in the fall. Nothing you can really do now.

Yes, that's what it looks like to me too. Applying pre-emergents in the fall help a lot. Plus if you have the time and energy you can pull it before it goes to seed. Seeds from the neighbors might still blow in so I go on the search early in the year and pull every little sprout.

Will Weed B Gone help? We did put in a pre-emergent in feb this year.

Pre-emergents help, but it's difficult to catch every seed. Plus application timing is critical. Some of the seeds may have germinated by Feb.

Weed-b-gone is a broad leaf weed killer and won't work on grasses. There is a Grass-b-gone that does a good job of killing grass, but it will also kill Burmuda grass. In fact, it's great for killing Burmuda grass! If you apply it very carefully to only the weed grass it will just kill a small patch of Burmuda grass around the weed grass, but if you're going to get down that close you may as well just pull it.

I know it's not easy and it's takes some time, but it's the only way I know of at this point. Good luck!