The *-ed* in all of your examples is a past-participle suffix. A past participle is not a **derived** form: rather, it is an **inflected** form of a verb (assuming you accept the distinction between derivation and inflection as grammatical processes in English). Most past participles end in *-ed,* but some end in *-⁠(e)n* instead (like *beaten*) and some don't end in either *-ed* or *-(e)n* (like *stood* or *hurt*). The past participle can have a passive meaning, so it can also be called a "passive participle". In the context of English, "past participle" and "passive participle" refer to the same verb form. But not all words ending in *-ed* are verb forms. Words belonging to other parts of speech can be derived from past participles. I think the most common type of derivation is past participle → adjective. Since verbs and adjectives are distinct parts of speech, it's best not to refer to such adjectives as "participles": instead, they can be called *departicipial adjectives* (a synonymous term is "participial adjectives"), which lets us reserve the term *participle* for the inflected form of the verb. That said, it's not always possible to figure out whether a word is a participle or a departicipial adjective. Here are some common texts for finding out whether a word is an adjective or a verb: - Can it be preceded by *very*? If so, it's an adjective. This test doesn't give positive results for me for any of your phrases. (But note that this test only works one way: it can't tell you that a word *isn't* an adjective. There are some adjectives that can't be preceded by *very*.) - Can it be preceded by *carefully*? If so, it's a verb. For me, this test indicates that the *-ed* words in all of your examples could be verbs. - Can you add the prefix *un-* (with the sense of "not", not with a sense of reversal)? If so, it's probably an adjective. For me, this test indicates that *calibrated* at least can be an adjective (since we certainly can say "an uncalibrated device"). The situation is less clear for *distributed, destroyed* and *founded.* There are dictionary entries for *[undistributed](https://www.merriam-webster.com/dictionary/undistributed)* and *[undestroyed](https://en.oxforddictionaries.com/definition/us/undestroyed)*, but "an undistributed product" and "an undestroyed house" both sound a bit weird to me. *Unfounded* clearly exists as the negation of a different sense of the word *founded,* but *"an unfounded company" doesn't seem acceptable to me. There are other possible tests, but I can't describe all of them. Some sources suggest that word order might be relevant, but I believe this is a mistaken view, so I haven't included this as a test. I think I've made it clear from what I've said above that there are many words ending in *-ed* that are not past participles/passive participles. (Most obviously, many past-tense verb forms end in *-ed,* but they are definitely not participles.)