This is incorrect.
Lei si era messa
is passsato prossimo, and means
she has / did put on ...
Lei si aveva messa
is trapassato prossimo, and means
she had put on ...
(edit) verb: mettersi http://www.wordreference.com/conj/ITverbs.aspx?v=mettersi
But if you read your link above: passato prossimo = 'Lei si è messa' (She has/did), for trapassato prossimo Essere (è) is conjugated into past time "Lei si era messa" (She had put on) -- so it is not incorrect. The thing is that these sentences with past perfect is always in a context of telling what 'had happened' before somthing else ... but the context is missing, because we only have 1 sentence. So it looks a bit weird.
Shouldn't it be "messo," and not "messa?" 501 Italian Verbs (book) only uses "messo" and never "messa."
I had posted a link to the verb mettere. That is not the verb used here. This verb is mettersi, a reflexive verb. Reflexive verbs always change to reflect gender.
look under trapassato prossimo, 3rd person singular here:
I'm not sure why it's "messa". If the dress had been a pronoun preceding the verb then the PP should match. That would have been "messo" Lei si l'era messo. Is that right? But what does "messa" have to match in this sentence?
The rule you quote 'If the dress had been a pronoun preceding the verb then the PP should match.' applies to verbs taking avere. When the verb takes essere as the auxialliary, then the ending reflects the subject (easy to remember because then there is often not a direct object).
Sorry I would like to ask if " Dove l'avevi trovata/trovato" are both correct because in previous lesson it had confused me a lot. Thanks
In your phrase there is a pronoun, it is small - l' - which we cannot really know if it is 'la' (her) or 'lo' (him) - unless by the conjugation of the PP (perfect particip). So if it is 'l'avevi trovatA' we know you found 'her', but it it it is 'l'avevi trovatO', we know you found 'him'. Usually the PP is not conjugated when conjugated with 'avere' - unless preceded by this short pronoun (l', la, lo), pronounced so quickly - to clarify the gender.
Thanks for explanation. I am still exercising to get a better sense. But for me it seems this rule happens only when the object is at the beginning of the sentence. Is that correct? One more examples from Dueling as well: "Avevo creduto la stessa cosa". In this case the object appears after the verb so it doesn't change to "creduta". Am I correct? Thanks
Yes, absolutely right!, it is only when the pronouns l', la, lo - are in front of a form of 'avere' that the PP following the 'avere'-form gets conjugated.
Does this sentence sound weird for an native english speaker? 'She had put a black piece of clothing on'
Where did you get "piece of clothing" from? "il vestito" is "the dress" "i vestiti" can be the clothes.
I saw somewhere "item of clothing" or "piece of clothing" but it doesn't matter. I understand better now, thank you for your help.
geee... the meaning... my answer of... "she had been wearing a black dress" was not accepted... funny, yet my italian friends are delighted that i am able to use this tense properly