Phrygian, Lydian, and Locrian
The three remaining modes. You'll meet them less often on the violin, but each has a strong, instantly recognisable colour.
Phrygian — minor with a flat 2nd
Natural minor, but the 2nd degree is a half step lower. That ♭2 sits right against the tonic and gives Phrygian its dark, tense, unmistakably Spanish flavour — flamenco is built on it.
Lydian — major with a sharp 4th
Major, but the 4th degree is a half step higher. That ♯4 makes the scale sound like it's lifting off the ground — bright, wondrous, unresolved-in-a-good-way. Film composers reach for it constantly (the leap at the start of The Simpsons theme is a Lydian ♯4).
Locrian — the one with no home
Minor with both a ♭2 and a ♭5. The flattened 5th means the tonic chord is diminished — there's no stable home to rest on. Locrian is a curiosity; you'll almost never meet a whole tune in it.
Try it
Try
Play a C major scale on the D and A strings. Now play the same seven notes starting from F (F G A B c d e f) — that's Lydian, and the B natural is the ♯4. Then start from E (E F G A B c d e) — that's Phrygian, and the F right by the E is the ♭2. Same notes, two completely different characters, just by choosing a different home.
The usual mistake
Fixing the "wrong-sounding" note by ear. In Phrygian your hand will want to raise the ♭2; in Lydian it will want to lower the ♯4. Those notes are the point of the mode — leave them where they are and let the mode do its work.