Please identify these two lawn weeds and advise on control
The first weed looks like Japanese stiltgrass. It is becoming a big problem and not just in lawns but also in natural areas. Of the 2 photos sent in it is the mot problematic. The following is the information we have on our website about the weed.
If you can hand pull as much as you can out of the lawn. Then in March apply a crabgrass preemergent to help prevent the seeds from germinating.
The other weed is wild violet. It tends to grow in shady, moist areas but will infiltrate a lawn.
In general, they are native, and they do have wildlife value. In particular, they are the larval food source for fritillary butterflies. You just may want to let them be. The following link has more information about control,