No electricity can be used or wasted if the lamp itself is turned off. It makes no difference if it has been turned off at the wall outlet or at the lamp itself.

It is the same situation as a flashlamp that has a light bulb supplied by a battery. If the flashlamp is switched off the battery inside it is still there, waiting to feed the light bulb with current, but the current can only flow into the light bulb when the switch on the flashlamp is turned on.

In Latin, the ablative absolute is usually found at the beginning of a sentence. It consists of a noun and a participle in the ablative case.

The ablative of accompaniment requires the appropriate case endings on the affected noun, and the preposition 'cum', which means 'with'. But the ablatives of instrument and of means require only the appropriate case endings on the affected noun. Neither one needs any preposition.

An ablative absolute refers to a construction in Latin that consists of a noun and participle or adjective in the ablative case, which is syntactically independent of the rest of the sentence. One can go to the library or search the internet to find an ablative absolute.

An ablative noun is a noun that is moving away from something. In English we mark it with the preposition "from". In Latin it's marked synthetically, i.e cactus changes to cacto in the ablative case.