"This cow has a lot of milk."
Translation:Vaca asta are mult lapte.
I had understood that "această (singular feminin) is normally used, but if the intent is to be emphatic, then "aceasta" is used instead, and it it placed after the noun.
I agree. It would be good to understand why this is sometimes 'this cow' and other times looks like 'the cow the this' (English simpleton, me, equates losing the accent as adding a definite article).
The adjective needs to agree in gender with the noun. "Lapte" is a masculine noun, "multă" is the feminine form.