～てある is quite different from ～ている, but it is often confused with it. With て, ある and いる function as supplementary verbs. In Japanese a supplementary verb is a verb that loses some or all of its literal meaning(s) to serve a specific grammatical purpose.
As you should know by now, て follows the 連用形. ～てある is exclusively used with verbs.
|Class||Example Verb||+ ～てある||Class||Example Verb||+ ～てある|
Grammar Note: For grammatical reasons to be discussed, 来てある is ungrammatical.
What is ～てある?
～てある shows a current state caused by someone's action. This state results from purposeful action done by someone, not something. It's used with transitive verbs, but を is not used for this usage. The basic pattern is (だれかに)XがYてある.
花が生けてある means that "the flowers have been arranged (by someone)" and the flowers are still arranged as such. 生ける is transitive. Do not confuse with 生きる.
The following example gives a static nuance. It shows that arrangements have already been made. So, the action is done by "someone", which is to "to inform". The resultant state is "to have informed".
To have informed her beforehand.
Similarly, ～ことにしてある has it that something is deemed as such by someone but really isn't. ～にする means "to make as..". For example, ばかにする means "to make an idiot of". Similarly, "Verb + ことにする" means "to decide that". Together, you can make sentences like the one below.
I decided to (make myself out to) be well (even though I'm really not).
Let's put some context to this statement. Your friend is in a stressful situation at home. In order to not worry her family, she has decided to be spirited on the phone to keep them at ease. This wouldn't be referring to actually seeing them in person.
(I) have set the clock five minutes forward.
State: The state is that the clock has been set five minutes forward.
Sentence Note: Ex. 3 shows that this pattern occasionally implies that the speaker is who did the action.
The glass has been broken (because of the actions of someone and still is broken).
State: The glass is still broken due to the fact that someone purposely broke it in the first place.
The questionnaires have been gathered.
State: The questionnaires are now gathered due to the actions of a person or people.
The window is open (by someone).
State: The window has been left open by someone.
The heater was turned on (by someone) and has been kept that way.
State: The heater has been turned on by someone.
The tree has been toppled down (by someone).
State: A person knocked the tree down and the tree is still on the ground.
His temperature was checked (by someone).
State: The person's temperature has been checked.
Dinner has been made.
State: The dinner is made.
The shirt has been washed.
State: The shirt is washed.
The book was placed on the desk (by someone).
The luggage was piled up in a clutter (by someone).
Practice: Translate the following.
～てある has other conjugations. For instance, you can still see ～てあった and ～てない. The grammar will distinguish the latter from the contracted form of ～ていない, ～てない, which will be discussed in this lesson.
The first floor [had been/was] rented to an old book store.
It [had been/was] written in the newspaper.
There isn't much furniture placed.
Other Supplementary Usages of ある
In である, a more ceremonious copula that is only practically used in the written language or in "連用形＋（は）ある" with adjectives, you can see the supplementary ある. Again, in case you have forgotten what the 連用形 is, here is a brief summary of how to construct it.
So, in case if you haven't noticed, you use ある in constructing the negatives with adjectives. ある → ない. So, Adj → 連用形 + (は) + ない. That has been the process all along. Now you have the option of lengthening the non-past form to 連用形 + （は） + ある, which is more likely to be used in longer phrases and in the written language. Again, as this is the supplementary verb ある at play, you should not think literally. Nor should you be thinking that English grammar would match the Japanese grammar as that's usually never the case.
Alligators are cold-blooded animals.
Man is the reed of thinking.
Although sad, but I have no regret.