What is the difference between 'flower' and 'rose'?
The difference lies entirely in the handshape. The sign for 'flower' uses a flattened 'O' handshape, where all your fingertips touch your thumb. The sign for 'rose' is initialized, meaning it uses the 'R' handshape instead. Both signs share the exact same movement of touching one side of the nose and then the other.
Do I need to sign 'red' before 'rose'?
No, you do not need to sign 'red' unless you are specifically describing the color of the rose. The sign for 'rose' inherently implies the flower itself, regardless of whether it is red, white, yellow, or pink. Only add color signs when that detail is important to your sentence.
Can I use this sign for a person named Rose?
Generally, names are fingerspelled in ASL. If you are referring to a person named Rose, you should fingerspell R-O-S-E. However, if that person is Deaf or heavily involved in the Deaf community, they might be given a specific name sign that incorporates the sign for 'rose', but you shouldn't assume this.