der Grieche
Greek man
A male person who comes from Greece or has Greek citizenship.
Der Wirt meiner Lieblingstaverne ist Grieche.
The owner of my favorite taverna is Greek.

Greek
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Greek man
A male person who comes from Greece or has Greek citizenship.
Der Wirt meiner Lieblingstaverne ist Grieche.
The owner of my favorite taverna is Greek.

'Grieche' is a noun of the N-declension. This means it takes the ending '-n' in the accusative, dative, and genitive singular, as well as in the plural. This is a common source of mistakes.
Ich habe gestern einen Griechen kennengelernt.
I met a Greek man yesterday.
The word 'Grieche' belongs to the word family around the country 'Griechenland' (Greece). The corresponding adjective is 'griechisch' (Greek).
Der griechische Wein schmeckt ihm besonders gut.
He especially likes the Greek wine.
The exclamation 'Alter Grieche!' is a fixed expression. It is used colloquially to express strong astonishment or surprise.
Alter Grieche, hast du das gesehen?
Good grief, did you see that?
Greek
'griechisch' and 'der Grieche' both have to do with Greece. The important difference is the part of speech and the usage: 'griechisch' describes something, for example food, music, culture, or language. 'der Grieche' means a male person from Greece. Learners may confuse the words because both have the same connection to the country. As a simple guide: for things and characteristics, use 'griechisch'; for a male person, say 'der Grieche'.

In der E-Mail schreibt sie, dass ihr Vater Grieche ist.
In the email, she writes that her father is Greek.
Am Wochenende kaufe ich griechischen Käse für den Salat.
On the weekend, I buy Greek cheese for the salad.