\cite at the end of a sentence

[FinnHuelsbusch]

Hello first of all.

I am quite new to LTex but really enjoy it so far. But I have one thing that really annoys me.
I have two scenarios:
1: A sentence where I want to point to a specific proof
This was described by \cite{someKey}.
2: A sentence that I want to give proof for by putting a cite at the end.
I want to give proof for this. \cite{someKey} A follow up sentence.

The first scenario works perfectly fine. But for the second one I get two 'errors'. The first one states that I have to put a space between the . and the \cite. While the second one regards to the A of the second sentence. There it says that the Words are only written with a capitalized letter at the beginning of a sentence. I understand why the errors appear but the suggestion does not seem ideal and I want/need to keep it that way. I can resolve this issue by simply ignoring the \cite{} command but this also does not seem ideal. Does anyone have a better suggestion?

Kind regards,
Finn

[FinnHuelsbusch]

Sorry, but doesn't anyone have a clue?