only if

[Anonymous]

Hi,
Please check these sentences and correct them.
1-1. The scars will be visible only if you look.
1-2. Only if you look, will the scars be visible.
2. Call me only if your cold gets worse.
3. Sign only if you agree utterly.
4. A triangle is isosceles if and only if the triangle has two congruent (equal) sides.
5. Take this medicine only if/when you have a temperature over than 40 degrees.
6. Answer me only when I ask you.
7-1. I think she calls on you only when you are out.
7-2. Only when you are out, does she call on you, I think.
Thanks in advance.

[Pete]

1-1. The scars will be visible only if you look. [Ok.]
1-2. Only if you look, will the scars be visible. [Ok, but omit the comma.]
2. Call me only if your cold gets worse. [Ok.]
3. Sign only if you agree utterly. [Ok.]
4. A triangle is isosceles if and only if the triangle has two congruent (equal) sides. [Ok.]
5. Take this medicine only if/when you have a temperature over than 40 degrees. [Ok.]
6. Answer me only when I ask you. [This doesn't sound complete. Maybe:
- Answer me only when I ask you a question.
- Answer me only when I call on you. ]
7-1. I think she calls on you only when you are out. [Ok.]
7-2. Only when you are out, does she call on you, I think. [Omit the first comma. Even then, it sounds informal. Ok in a conversation; use 7-1 in a more formal context.]