In French the word is a simple noun meaning place or location, but the English expression tends to be limited to the half-translated phrase "in lieu of"*, meaning "instead of" or "in place of".
En...
It can be if the reference of what it refers back to is absolutely clear, but 99% of the time it isn't absolutely clear.
Example
I have to fly to Miami this weekend. This is a problem.
What's the...
The word this can be used by itself, but only if its referent is clearly and unambiguously stated. The reason many English teachers caution beginning writers not to use this alone is that many use it...