German and English use the articles in similar ways, however there are some exceptions. Just because you see a noun doesn’t mean you should always attach an article in front of it.

In German, it’s common to see articles used after a preposition (die Präposition) : in der Nacht (at night)

With parts of the body : die Augen (eye)

With  an institution (die Anstalt) or organization (die Organisation) : die Schule (school)

With clothing (die Bekleidung) : das Hemd (shirt)

Measurements : das Kilo (kilo)

Name of a country (die Heimat) : die USA (USA)

Month (der Monat) : der Juni (June)

Seasons : der Sommer (summer)

Famous people or historical figures : die dietrich ([Marlene] Dietrich)

Streets : die Beethovenallee (Beethovan Street)

General/vague/abstract nouns : das Leben (life)

Fixed expressions : in der Tat (in fact)

*Articles in German are not used with instruments : Er spielt Piano (he plays piano)

Also not used with professions and nationalities after the verbs sein, werden and bleiben : Er ist Doktor (he’s a doctor)