Snape, Voldemort, and teaching (was: Question..)

[potioncat]

No: HPFGUIDX 135376

 
> Julia here:
> It's really strange - that Snape's case. According to him in OotP 
he 
> started working 14 years ago (which can be after Potters death!) 
BUT 
> in HBP he says to Bellatrix: 'I had sixteen years of information on 
> Dumbledore to give him when he returned'. How can this be? In HBP 
he 
> is refering to him staying in Hogwart so unless he helped Hagrid, 
> Filtch or cook with other hause elves he had to teach! When is he 
> saying the true? I am under the impression that he isnt honest with 
> Bellatrix but then, shouldnt Bellatrix at least knew when he became 
> a spy at Hogwarts??
> It's really confusing, someone has an idea??

Potioncat:
We know Snape was spying for LV at Trelawney's interview and she had 
been teaching for 16 years when Snape was at 14. She says that Snape 
was also applying for a job when she was interviewing with DD. So 
it's very likely that on LV's orders, Snape began to seek employment 
at Hogwarts but it took a few years to get the job. In the meantime, 
he may have had other reasons to be hanging around DD. Or he might 
have continued his association with Slughorn.

Suppose Snape applied for the DADA position two years running, then 
the potions position (hard to say) also opened up when Slughorn 
retired.

Or it could be maths.