Learn Dutch: Het enige was het slechte weer. - The only thing was the bad weather.

In Dutch, you do not need to add a word for "thing" when talking about abstract concepts. You can just take the adjective enig (only), add an -e, and put het in front of it. Het enige perfectly translates to "the only thing".

If I want to say "the only one" about a person, do I still use Het enige?

No. When referring to people or de-words, you use de enige (the only one). You use het enige when referring to abstract things or het-words.

I often hear Dutch people say het enigste. Is that the same as het enige?

You will definitely hear het enigste in casual speech to mean "the only thing", but it is technically incorrect! Enig also means "cute" or "adorable", so grammatically, het enigste actually means "the cutest thing". It is much safer to learn and use het enige.

Why does slechte get an -e at the end if weer is a het-word?