Why is this not a sentence?

[Kingcomicbook]

My English teacher says this is not a proper sentence : "Doing everything from aiding the escape of slaves to giving equal education to black children."

Why is this not a proper sentence?

[PCgamer324]

no noun

 

who's doing the doing

[Ddave]

It lacks... something.

It doesn't make complete sense ?

 

Here's my fix:

 "We are doing everything from aiding the escape of slaves to giving equal education to black children."

We = subject

are = linking verb

others = predicate ?

Question: Who is doing everything from aiding the escape of slaves to giving equal education to black children ?

Answer: We

 

Question: What are we doing ?

Answer: Everything from aiding the escape of slaves to giving equal education to black children

 

 "Doing everything from aiding the escape of slaves to giving equal education to black children is a noble act."

Don't know how to explain this one.

 

It's been a while since I went to the technicalities of the language so I can't recall everything, but I hope you get what I mean.

 

[Omon_Ra]

11 minutes ago, Kingcomicbook said:

My English teacher says this is not a proper sentence : "Doing everything from aiding the escape of slaves to giving equal education to black children."

Why is this not a proper sentence?

As @PCgamer324 said, there's no noun/subject in the sentence. As it stands now it's just a phrase. There also could be a comma between 'slaves' and 'to;' but depending on the new sentence, I think it could be optional? English grammar (really, the English language as a whole) is one of the most irrational and confusing things ever.