What is the basis structure of a German sentence?

The basics 

Subject-> Verb-> Direct object

Subject- Noun (naming word), Pronoun (stands in place of noun-er, sie, es)

Verb-Doing word, agrees with the subjects, ends in -en

Direct object- the object affected by the action of the verb, in the accusative case

Reminder: Den (M), die (F), das (N) die (Pl)/einen (M), eine (F), ein (N) 

Sample sentence in English- The Man (SUBJECT) buys (VERB) the apple (DIRECT OBJECT)

Sample sentence in German- Der Mann (SUBJECT) kauft (VERB) den Apfel (DIRECT OBJECT)

Note: the direct object takes the accusative case- der Apfel (nominative)-> den Apfel (accusative)

Remember: the accusative is one of the 4 cases in German. Nominative, accusative, dative and genitive! 

Recognising the cases will help you make sense of a sentence! 

Once you've mastered this, we can add more elements and make more complex sentences.