Using 〜ています with intransitive and transitive verbs


I am currently learning that 〜ています can be used to express a state that
resulted from a previous action, e.g.

> でんきがついています。

All examples in my textbook (Minna No Nihongo - Lesson 29) use intransitive
verbs. But there exists a transitive counterpart to つく, namely つける. My
question is now, what is difference of the earlier mentioned sentence to the
following one

> でんきをつけています。

Is the semantic of 〜ています in the second sentence different from the one in the
first sentence?




Transitivity is not important to determine the meaning of ている. It depends more
on the meaning of each verb:

| progressive ("is doing") | perfect aspect ("has done")  
---|---|---  
**transitive** | ～を食べている  
is eating ～ | ～を超えている  
has surpassed ～  
**intransitive** | 走っている  
is running | 死んでいる  
has died (is dead)  
  
As for 電気をつけています, つける is usually an easy instant action, so it can mean "I've
(already) turned on the light (of the room for you)", but 電気をつけてあります is more
common for this meaning. When there are many lights, 電気をつけています can mean
"(Currently) I'm turning on (all) the lights (on this floor)" as well. It
depends on the context.

