Questions & Answers about Ellas van a la estación.
Why is it "a la" here, but in other sentences we use "al"?
The word al is a contraction that only happens when the preposition a (to) meets the masculine article el (the). Because estación is a feminine word, it uses the feminine article la. The words a and la never combine, so they stay as two separate words: a la.
How do we know "estación" is feminine if it doesn't end in an "a"?
Does "van" mean "they go" or "they are going"?
It can mean both! In Spanish, the simple present tense can translate to either the simple present ("they go") or the present continuous ("they are going") in English. You just use the context to decide which one sounds more natural in English.
Is the word "Ellas" strictly necessary at the start of the sentence?