Agree with Shasta daisy (Leucanthemum × superbum) likely for the first, second looks like lily-of-the-valley (Convallaria majalis), third is a euphorbia of some variety and the last one is Cuckoo Pint (Arum maculatum) I think.
A trowel in the hand is worth a thousand lost under a bush.
Could be wrong. Whilst I agree the 3rd photo looks like Euphorbia, the flowers look suspect. Is it woody and do the flowers smell? Looks a bit like Daphne Odora to me.
If you want rid of the thug (the wild arum), you'll need to dig carefully and deeply to remove the knobbly tubers, or they'll just grow again. I've been trying to get rid of a large patch in my garden today...
"The one who plants trees, knowing that he will never sit in their shade, has at least started to understand the meaning of life." Rabindranath Tagore
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The bottom one is Wild Arum and a real thug.