Question

I did not know anyone else was here (change affirmative sentence)​

Answer 1

I knew someone was here.

The sentence above is an affirmative sentence. An affirmative sentence is a sentence that states something assertively - as a fact.

To convert the sentence to an affirmative sentence, remove all negative sentence clauses (not) and ambiguity in the sentence.

We remove the negative sentence clause (did not), which is located before the verb, and the ambiguity clause (anyone else) which we convert to an affirmative clause (someone).

Thus, the sentence becomes: I knew someone was here.