Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
And here's another cool tip: to make precise adjustments, hold down the ALT key while moving the object to position it.
Source: https://gamerant.com/the-sims-4-guide-move-objects-up-down/