(1) That's what I am looking for.
(2) That's what I was looking for.
(3) That's what I have been looking for.
Is the sentence (1) wrong? What's the difference in meaning between the three above ? I always thank you all, angels^_^
Is there a difference in meaning? Not really; the meaningful part isn't in the auxiliary verbs "be" (whatever its form:
am, was, been) or "have." As auxiliary verbs, they are simply part of the skeleton of the sentence, playing grammatical functions. The auxiliary verbs would make a difference if they are needed to mark "past tense" (
was, had), to signify that it all happened in the past; but if this is happening "now," "tense" is irrelevant, and all three are possible.
Now, in the "now,"
which one would people use? There is no universal answer. It depends on who you ask, and how they intuitively match verb paradigms and reality (i.e. perspective).
So the answer to the question,
is (1) wrong?, is no, it's not wrong. In the "now," choosing one option doesn't exclude the other two options. Sometimes, the discourse itself selects the verb form. If someone asks,
Is this what you are looking for?, then it's quite natural to answer,
That's what I am looking for, matching "are" with "am."
And there is something else to consider, which may not be what you had in mind.
Look(-ing) for is an idiom, and it can be
specific (someone/something in particular) or
general/broad. If I'm having a bad day, and someone gives me a hug, (1), (2), (3) can be specific ("a hug") or broad ("attention, "understanding," "comfort," etc.)
