There is no problem with the extra_english.lang file. Make sure you used the option "NoteText" when you select a note, not the name.
For the respawn monster part:
I'll give you an example script:
void OnStart()
{
AddEntityCollideCallback("Player", "SCRIPT_AREA_NAME_HERE", "SpawnMonster", false, 1);
//The false makes it so the callback won't get removed once triggered
}
void SpawnMonster(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("ENEMY_NAME_HERE", true);
//All the path nodes go here!
AddEnemyPatrolNode("ENEMY_NAME_HERE", "PathNodeArea_1", 0, "");
AddEnemyPatrolNode("ENEMY_NAME_HERE", "PathNodeArea_2", 0, "");
AddEnemyPatrolNode("ENEMY_NAME_HERE", "PathNodeArea_3", 0, "");
}
If you instead want the monster to stop reappearing after, let's say, 3 deaths, or you want the monster to appear RIGHT after you respawned instead of going through a script area first, you will have to do a bit more work that will include a Local Variable and/or the command
CheckPoint (string& asName, string& asStartPos, string& asCallback, string& asDeathHintCat, string& asDeathHintEntry);
Might want to know that the monster WILL know your position and WILL run full speed towards you after he's set active again.
If you instead ment a way of reappearing like a patrolling grunt who is not supposed to know your position once spawned, you can try making a bunch of grunts set inactive at the same position, and at every death(checkpoint command used)you set a variable higher by 1 and the enemy_variable will be set active. I think 5 should be the max, I don't think anyone would fail 5 times there. And if someone does, you can add a troll message like "the enemy will no longer appear, because you suck too much to avoid it" or something.