Nach dem langen Training bin ich körperlich müde, aber innerlich ruhig.

After the long training I am physically tired but calm inside.

Breakdown of Nach dem langen Training bin ich körperlich müde, aber innerlich ruhig.

• sein: to be
• dem: the; (masculine or neuter, dative)
• ich: I
• lang: long

Questions & Answers about Nach dem langen Training bin ich körperlich müde, aber innerlich ruhig.

Why is it dem Training after nach, and not das Training?

The preposition nach (in the sense of after in time) always takes the dative case.

• Training is a neuter noun: das Training (nominative).
• In the dative singular for neuter, das changes to dem.

So you get:

• Nominative: das Training
• Accusative: das Training
• Dative: dem Training
• Genitive: des Trainings

Because nach needs the dative, you must say nach dem Training, not nach das Training.

Why is it langen in dem langen Training and not lange?

The ending -en on langen comes from German adjective declension.

Rule here:

• There is a definite article (dem).
• The noun is in the dative singular (because of nach).
• With a definite article in the dative singular (all genders), the adjective takes -en.

So:

• Nominative: das lange Training
• Accusative: das lange Training
• Dative: dem langen Training
• Genitive: des langen Trainings

That is why it must be dem langen Training, not dem lange Training.

Why does the sentence say bin ich and not ich bin?