(Japanese) How is the verb "shiteru" related to/derived from "suru"?

Question

I practically can't find the verb "shiteru" in ANY online Japanese-English dictionary.

I'm guessing that "shiteru" has something to do with "suru" but I can't point my finger on it.

The "ru" in "shiteru" seems to refer to a base form, which is even MORE perplexing, because the base form of "suru" is, well, "suru"!

And finally, do
"Nani o shiteru no" and
"Nani o shite iru no"
have the same meaning?

The "shite" in the second sentence is obviously a form of "suru", and "iru" is a base-form verb. How about "shiteru"?

Thanks a lot for your help!!! ^_^

(Note: If you think that this has anything to do with certain English swear words, then you are wrong, and please don't answer this question.)

Answer 1

"shite ru" is grammatically incorrect. Strictly speaking, you have to say "shite iru". But many Japanese use that incorrect phrase, especially colloquially. "shite ru" sounds a little bit friendly to me.

[Another example]
I can eat sashimi.
-> watashi wa sashimi wo taberu kotoga dekiru.
-> watashi wa sashimi ga tabe rareru.

Both are correct. "kotoga dekiru" and "rareru" both mean can.

# watashi wa sashimi ga tabe reru. ("ra" is dropped.)

This is grammatically incorrect. But many Japanese use it.

Those chatty expressions are called "i nuki kotoba" and "ra nuki kotoba", which are literally translated into "words dropping the i" and "words dropping the ra" respectively. Some strict persons criticize for using incorrect Japanese like those.

Answer 2

Shiteru is a shortened form of shite iru (the Tokyo dialect typically uses "shiteru") , and basically means "is doing."

Answer 3

"Shiteru" and "shite iru" are same. (shite +iru = shiteru)

Therefore, "Nani o shiteru no" and "Nani o shite iru No" have the same meaning. (Both means "what are you doing?")

Answer 4

thats true, its means doing