Selecting group of objects

Hi!

I am searching a way to easily add selections. I can hold SHIFT while selecting objects but in fact it DOESN'T ADD selections but only INVERTS it. So if I already have something selected, I hold SHIFT to grow my selection but then selected objects get deselected when I cross-through them with the new selection area. Is there any key to ONLY-ADD selection?

This SHIFT-selecting is soooo.... I have no words. So non-intuitive. Makes selecting numerous objects a nightmare.