Second is a violet
Third looks like a primrose but early to flower.
forth could be a daffodil or if it dies down completely it will send up a flower in late July to September. In that case it goes by the common name of suprise lily. There are several different families that use the same common name so I can not tell which family it is.

Thank you maifleur!

I found out that #1 is creeping bellflower unfortunately.

#4 I thought last year that it was maybe a daffodil but it never flowered.

Is that violet an invasive species too? I thought I read somewhere about a violet that is invasive.

People use the term invasive too much. Violets can be weedy in that the seed pods have from a few to many seeds. The pods when they open can spray the seeds outward. Each seed can then expand the territory. I personally like the ones that are in my yard because their are many animals that eat the plants.

Looking at the leaves I believe that yours are the violets that have a reddish purple flower but before you decide to pull up or spray watch to see what color they are as wild violets can be many colors. The rarest in this area are the red flowered followed by two types of yellow flowered ones. You might look in the violet forum and post your violet picture. Someone might be able to tell you more about it.