"She needs a coat."
Translation:Ela precisa de um casaco.
"Ela precisa dum casaco" is perfectly fine in BP (Brazilian Portuguese). But we don't use the contractions from the indefinite articles in formal/written language. So you can say "duma, dum", but you can't write them, you must write "de uma, de um". Concerning contractions from definite articles, all of them are accepted as far as I know, the only exceptions are "para o, para a" (you can say "pro, pra", but not write). I hope this helps! =)
Yes thanks. Written and spoken language... I'll confront my teacher with this...keep you posted!
you mean European Portugese? Maybe yes, it's very common like also: pela (por a), pelo,(por o) da (de a), do (de o) etc. etc.
Yes. I shouldn't have said "such" contractions though, it sounds like Brazilians don't use any. As far as I know, just the ones that contract a preposition with the indefinite articles "um/uma".
I wonder what the difference is between a jaqueta and a casaco. Is it a man/woman difference?
Jackets tend to be shorter length, coats longer length, either may be mid length.
A jacket length may reach to the waist or the thigh and may be light, heavy, specific purpose: motorcycle jacket, suit jacket & etc.
Suit jacket, suit coat, sport coat, blazer, tend to be thigh length, reaching the index finger knuckle or hand knuckles when arms are dropped down and resting at the sides.
Clothing article names for jackets and coats may overlap, such as in suits, but coat lengths may reach below the knees.