This flat was politely rejected by The Enigma, but I still like it. Actually, I'm quite proud of it.The keywords IMPOSTER and IMPOSER represent a phrase and a word, in that order. The phrase and word differ by only a single letter, as reflected in the keywords. The extra letter in the phrase is in exactly the same place as the T in IMPOSTER - which is the extra letter in the two keywords. 

I met a girl at Venice beach, 

While hanging on the rings.

Her English wasn't perfect,

Surely not the king's.

For "she and I" she said IMPOSTER -

I admit it had a little sting.

But who cares about syntax and grammar,

When in the sand and waves you can IMPOSER. 

Answer:

 

I met a girl at Venice Beach,

While hanging on the rings.

Her English wasn't perfect,

Surely not the king's.

For "she and I" she said ME AND HER -

I admit it had a little sting.

But who cares about syntax and grammar,

When in the sand and waves you can MEANDER.

 

Credit: Joseph Appel