Questions & Answers about Deine alte Waschmaschine war sehr laut.
Why does the adjective alte have an -e at the end?
Because it comes right before a feminine noun (Waschmaschine) and after a possessive article (deine). In the nominative case (when the noun is the subject of the sentence), an adjective following deine, meine, keine, or eine gets an -e ending for feminine nouns.
Why is it deine and not just dein?
The possessive article must match the gender of the noun it belongs to. Since Waschmaschine is a feminine noun (die Waschmaschine) and it is the subject of the sentence, the article takes the feminine nominative ending -e.
Since laut is also an adjective, why doesn't it get an ending like alte?
In German, adjectives only get grammatical endings when they are placed directly in front of the noun they describe. Because laut comes after the verb (war) and isn't attached directly to a noun, it stays in its basic dictionary form.
What tense is the verb war?