黒い

1. Origins, structure, and basic meaning

• Structure: 黒い, read くろい, consists of the color stem 黒 plus the i-adjective ending い.
• Basic usage: It modifies a noun as in 黒い線, or marks a color change as in 黒くなる.

2. Common pitfalls and similar expressions

• Forms and inflection
  • Use 黒い before a noun; before なる, use the adverbial form 黒く, and do not form 黒いなる.