真っ直ぐ

1. Origins, structure, and basic meaning

• Structure: 真っ直ぐ, read まっすぐ, is a conventional form joining true 真 and straight 直ぐ with the geminate っ.
• Basic usage: 道を真っ直ぐ進む means moving straight ahead, while 針金を真っ直ぐにする means making something unbent.

2. Common pitfalls and similar expressions

• Distinguishing meanings
  • It appears as 真っ直ぐ modifying movement and as 真っ直ぐに when making a state, so attend to its grammatical role.