Raspberries?

You could mow them all to the ground this fall and then, if you get no berries at all next year, they were summer bearing. ;-)

OK, let me think of something less drastic.... Look at the canes. If they are fall bearing, all the canes will have fruited. If half of the canes look like they only had leaves and the other half (more or less) show signs of used flower/fruit clusters, then it is summer bearing. How's that?

Steve PS If you decide they ARE summer bear> I just bought a house with raspberry canes planted in the back yard.

Fall or everbearing varieties would have the remnants of berry-producing at the top of the feshest canes (with reddish bark). These young canes, which will produce an early summer crop next year, may also still retain some yellowing leaves. Older canes which produced an early summer will have long dried up in the late summer and will have a silvery, dead look,

The easiest thing to do is leave everything in place until early spring, then cut out anything that doesn't show fresh buds, and thin out the remaining canes. I prune my fall bearer to allow both an early crop and a late summer crop.