butterflies ID please

[hopeless]

Hi,

I am getting a bit lost between argus brown, chalkhill blue and common blue.
Could you please ID the following butterflies, and maybe explain why they are what they are?
Thanks for you help.

Hopeless


1-



2-



3-



4-

[GuyF]

Numbers 1 and 2 are female Chalkhill Blues. The chequered wing margin rules out Common Blue, and they can be separated from Adonis Blues by the white, not blue, markings around the orange spots on the hindwing upperside.
Number 3 is a female Brown Argus, the orange markings on the upperside are much bolder than any of the other blues, and the layout of the spots on the underside is also diagnostic.
Number 4 is a mating pair of Chalkhill Blues, again the chequered wing margin means they're not Common Blues, and the very pale colouration of the male (on the right) is typical of this species.

Guy