Learn Farsi: شکلات شیرین است.

In spoken Farsi, the formal verb است (is) is almost always shortened and attached to the end of the previous word. Because شیرین ends in a consonant, است turns into a simple "-e" sound. So, the sentence is spoken as شکلات شیرینه (shokolāt shīrine).

Why isn't there an article or marker before شکلات?

Farsi handles general statements about uncountable or mass nouns exactly like English does. When making a universal claim about "chocolate" in general, you just use the bare, singular noun without any definite or indefinite markers.

If I wanted to talk about individual candies instead of the general flavor, how would I say "Chocolates are sweet"?

If you are referring to multiple individual pieces, you would pluralize the noun with ها and change the verb to the plural form هستند. That sentence would be شکلات‌ها شیرین هستند.

Since شکلات is a loanword, where does the syllable stress go?

Even though it is a borrowed word, it still follows the standard Farsi pronunciation rule for nouns, which places the stress on the very last syllable: sho-ko-LĀT.