Can I use "that" 2 times in a sentence next to itself?
Yes, the words "that that" can appear in a grammatically correct sentence. The first "that" is a relative pronoun (typically used to clarify something), and the second "that" is a demonstrative pronoun (specifying the subject matter at hand).
For example: "Are you looking for these parts for your vacuum? I found the ones that that machine uses."
Technically, you can use
that infinite times in a row and make a proper sentence.
Here is an example:
That that that that that used was correct.
- The first
thatis specifying which
thatyou are referring to.
- The second
thatis the object in which you are refereeing to.
- The third
thatis introducing a subordinate clause expressing a statement or hypothesis.
- The finale
that thatfollows the first two bullet points.
Think of it as an abstracted version of the following sentence:
The wrench that the plumber used was correct.
The wrenchis the first
The plumberis the second
This string can actually be repeated infinitely, with punctuation, and still make a proper sentence.