I have been learning English for several years now, but I cannot explain properly the reason that past tense verbs can describe nouns.
The data presented in the above graph suggests that ...
The written evidence found was illegible.
I believe the above sentences are grammatically correct.
Here, in the first example, 'presented' describes the noun, 'data'.
In the second example, the noun 'evidence' is described by 'written' and 'found'.
To express the above sentences alternatively, I think they can be written as:
The data that was presented in the above graph suggests that ...
The written evidence that was found was illegible.
So, can I assume that 'that was' is omitted in both of the sentences?
How would you explain effectively and correctly the construction of this type of sentences to a student?