Thanks. Grammar tip about "il / elle est" versus "c'est".
I've just made a mistake. A useful explanation about the mistake appeared as well as that crying owl. Thank you to whoever wrote or organised the explanation. (I've made several thousand mistakes in my duolingo career, but I get annoyed at that crying owl because of the much smaller number of Duolingo mistakes.)
The tip was: "In French, you have to use "c'est" for modified nouns (e.g. "C'est une fille" for "She is a girl"), but you have to use "il est" or "elle est" for unmodified nouns (e.g. "Elle est médecin" for "She is a doctor")."
This is the sort of thing I need. Thanks again,
I still don't know what an unmodified vs. modified noun is. This tip was almost helpful for me.
Aha! "He is a lawyer" can be translated two ways, depending on whether or not you want to use "un": "Il est avocat" versus "C'est un avocat." In the second case, avocat is modified by "un," the article.
"C'est une fille" versus "elle est fille."