Is this correct: "Es ist ein Tisch. " Tisch is masculine, not neutre. And I found this as part of a lesson. I think it has to be Er is ein Tisch is masculine. I think it has to be "Er ist ein Tisch". Thanks for the help :)
No, the answer "Es ist ein Tisch" means, "it is a table." Regardless of the gender of the noun it is describing, Es is still just being used as the word for "it." Remember, Er=he, Es=it. It is grammatically correct to say "it is a table" rather than "he is a table," as the thing being described is an inanimate object.
When describing nouns in german, it doesn't really matter if it's masculine or feminine unless you're using something that requires definition (like ein/eine or Der/die das). If you're saying "That is the table (Das is der tisch)" the "der" is the masculine definite article. Whereas you're saying "It is a table (Es ist ein tisch)" the article ein is masculine, but the subject "it (es)" is not.
This got complicated, let me try again: the only time you need to know masc/fem/neu is in the article right before the word. "Der Tisch" "Ein Tisch". Everywhere else in this language, it's not really important.