Thread: наполнять, заполнять

Интеллектуальные задачи наполняли его энергией.

I cannot use заполнять in this case?
Both verbs are not translated as fill?

In physical meaning на-полнять ("на" as "atop") is more suitable for filling something to some (usually full) level of height. Examples: cup of tea, river (by rain), construction groundwork (by concrete) and so on.
За-полнять is about volume (not height). It is more suitable for talking about filling some (usually full) volume.
In most cases they can be used interchangeably.

"наполнять энергией" is idiom.
"пере-полнять энергией" ("пере" as "over top") is idiom.
"заполнять энергией" is not idiom.

Alex80

is (not) an idiom (all the three cases)
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Whenever you refer to a word as to be a title of a group of things, you have to use an indefinite article (a/an).
Airbus is not a car.
Train is a vehicle. (one of the vehicles known)
Get the jump of something is not an idiom (as opposed to the 'Get the hang of sth', which is an idiom -- the latter one can be titled "IDIOM")
- When you're talking about titles - use indefinite articles
- When you're talking about things themselves - use definite articles

*excuse my pickiness