"The woman eats apples."
Translation:Die Frau isst Äpfel.
das is the neuter nominative singular article, as in das Messer, das Pferd, das Kind, das Mädchen (the knife, the horse, the child, the girl), which are all neuter nouns.
die is the feminine nominative singular article, as in die Gabel, die Frau, die Person, die Katze "(the fork, the woman, the person, the cat), which are all feminine nouns.
I just started German, but it seems to me a small vowel change is way too subtle to hear in many situations, likely even for native speakers. If it is an object, the singular will have an indefinite article. If it is a subject, the singular needs a singular verb and the plural a plural verb. These are all much easier to hear.
That would be logical :), but "essen" is an irregular ("strong") verb. In the present tense, some irregular verbs use a different vowel for the "du" (= you singular informal) and the "er/sie/es" (=he/she/it) verb forms. These are exceptions and have to be learned by heart.
essen (to eat)
It's the same with some other irregular verbs such as "lesen" (to read):
lesen (to read)
No, "isst" (= "eats" or "is eating") is used with "he/she/it" or nouns that can be used instead of "he/she/it" such as "the man" (der Mann), "the woman" (die Frau) or "the book" (das Buch). "Isst" is not only used with feminine nouns or pronouns. The same applies to "eats" or "is eating" in English.
- Frau must be capitalised; it is a noun
- die Frau is just one person, so the verb form has to be isst. essen would be for wir (we) or for sie (they), i.e. multiple people
- Äpfel has to be capitalised and the first letter has to have an umlaut -- Apfel is the singular but the plural is Äpfel (or Aepfel if you can't type letters with umlauts).
Yes -- in the sense that "am, is, are" all mean the same thing: they're all the present tense of "to be".
But they are not interchangeable -- for example, you can't say "you am" or der Haus.
"you" goes with "are" and Haus goes with das.
der is for masculine nouns, die for feminine ones, and das for neuter ones -- and the grammatical gender of a noun basically just has to be learned.
For example, die Sonne (the sun) is grammatically feminine but der Mond (the moon) is grammatically masculine -- not for any particular reason. Or das Mädchen (the girl) is grammatically neuter while die Person (the person) is grammatically feminine.