Formal:
* The scientist's claims were so bold that they needed to be substantiated with concrete evidence.
* The prosecutor presented a compelling case, but the defense attorney was able to effectively substantiate their client's alibi.
* It is important to substantiate any accusations with credible sources before making them public.
* The company's financial report failed to substantiate its claims of profitability.
* The historian was able to substantiate his theory with primary source documents.
Informal:
* I'm not just making this up, I can substantiate it with photos!
* Can you substantiate that claim with anything other than hearsay?
* The witness's testimony wasn't enough to substantiate the charges against the suspect.
* I'm going to need some more evidence to substantiate your wild story.
* She couldn't substantiate her claims of being a psychic, so we all wrote her off as a fraud.
Note: "Substantiate" can be used with both direct and indirect objects.
* Direct Object: She substantiated her claims.
* Indirect Object: He provided evidence to substantiate his argument.