Learn Hardcore German: Der windige Morgen am See ist frisch. - The windy morning by the lake is fresh.

In German every noun has a gender. Morgen (morning) is masculine, so in the nominative singular it takes der. Here Der windige Morgen is the subject of the sentence.

Why does the adjective windige end with -e?

Because it’s an attributive adjective following a definite article. After der in the nominative masculine singular, adjectives take the weak ending -e (weak declension):
– der + windig + -e + Morgen

Why doesn’t frisch have any ending?

Here frisch is used predicatively (it follows the linking verb ist). Predicative adjectives are never declined, so they appear in their base form.

What’s the difference between placing an adjective before the noun (as in windige Morgen) and after the verb (as in ist frisch)?

An attributive adjective (before the noun) must be declined to show case, number and gender. A predicative adjective (after a verb like sein) simply describes the subject and remains uninflected.

What does am See mean and why is it am?

am is the contraction of an dem. It introduces a dative prepositional phrase of location. am See literally means “at the lake.”

Could we say an den See instead of am See?

Yes, but that would use the accusative case and imply motion toward the lake (“to the lake”). am See (dative) indicates a static location: “at the lake.”

Why is ist in the second position and not at the end?

German main clauses follow the verb‑second (V2) rule: the finite verb must be the second element. Here the entire subject phrase Der windige Morgen am See occupies first position, so ist comes second.

Could we omit the article and say Windiger Morgen am See ist frisch?

No. In standard German, singular countable nouns in attributive position generally require a determiner (article). Omitting der would sound ungrammatical outside of headlines or poetry.