1. Form and meaning
Adjectives before nouns take endings according to case, gender, number and article type. Definite articles usually carry much of the grammatical information; with no article or an indefinite article, the adjective often carries more. Participles used before nouns decline like adjectives.
When you study this pattern, identify its communicative purpose first. Then check the verb form, case and word order. German clauses are easier to control when you learn the connector together with the sentence pattern it requires.