We use as long as to refer to the intended duration of a plan or
idea, most commonly referring to the future. We always use the present simple to
refer to the future after as long as:
- We are very happy for you to stay at our house as long as you like.
- I’ll remember that film as long as I live. Not: … as long as I will live.
As long as or so long as also means ‘provided that’,
‘providing that’ or ‘on condition that’:
- You are allowed to go as long as you let us know when you arrive. (Cambridge)
- As long as he will come back to me, I am a
happy kid.
- I thought it was good as long as this would be the
place he'd always come back to.
Out of context, it's not clear what these two sentences above are intended
to mean. They're poorly formulated and use incorrect tense sequences.
- As long as you'll be here to supervise them,
it's okay.
The „will“ (expressed by the contracted form you'll) is
understood to mean „are willing“. It means „za předpokladu/pod
podmínkou, že budeš ochoten“. It doesn't refer to the future („… tak
dlouho, jak …“). Alternatively, „as long as you'll be here“ can be
understood in a conditional (not a future)
sense as explained in emsa Věty
podmínkové 16.23.43:
Spojka on condition that se zčásti pociťuje jako
suma svých složek, což se projevuje v tom, že se věta jí uvozená může
chápat též jako přívlastková (vztažná po substantivu condition),
v níž neplatí omezení o užívání futura, srov.
- I'll tell you on condition that you won't (vedle don't) tell anyone. Řeknu
vám to pod podmínkou, že to nikomu neřeknete.
(V případě jako I told you on condition that you would keep it to
yourself [Řekl jsem vám to pod podmínkou, že si to necháte pro sebe] jde
ovšem pouze o větu vztažnou.)
But there's no need to use „as long as you'll
be here“. „As long as you're here …“ is standard usage.
See as
long as + will/going to? (Word Reference).