1. Concept explanation
Deklination is "declension", that is, nouns, pronouns, and adjectives make formal changes according to the requirements of predicate verbs/prepositions/adjectives, etc., to show their respective component status.
The so-called n-Deklination, as the name suggests, is the declension of with an additional n or en at the end.
The Chinese translation of "masculine weak change" is quite considerate. "masculine" reminds you that the subject of is " masculine noun " (accounting for 99.99%). "weak change" refers to " with n or en added to the end of the word".
2. Classification and examples
Let’s look at a dialogue first:

In the question, Herr is the fourth object of kennen. assumes that Herr is a common masculine noun, so here it means that the definite article needs to be changed to den:
Kennen Sie den Herr da?
But in fact, Herr belongs to n-Deklination, which means that when has four cases, it must be written as Herrn.
Kennen Sie den Herrn da?
In the answer sentence, der Herr is the subject, that is, the first case. It can be said normally:
Der Herr ist mein Mann!
But please keep in mind that masculine weakly changed nouns not only need to add a suffix in the fourth case, but also the same in the second and third cases.

In order to facilitate memory, grammarians have summarized several types of yang weak (you only need to pay attention to the endings of such words):

The first type is masculine characters ending in e, such as Junge, Kollege, Experte, Chinese ...
The second category is the masculine animals ending with e, such as Löwe, Rabe...
The third category is -ist, -ent, Masculine nouns ending in -at (all people and things are acceptable), such as Polizist, Student, Automat, etc.
3. Special cases
But as you might expect, there are always exceptions to German , so please note down the annoying special cases:

a. In addition to adding n, some abstract nouns also need to add s
in the second case. How do you understand this? The general rule of weak positive changes in and is that it breaks the rule of adding s or es to the second cell, just add n. For example, des Herrn (the basic law of weak yang), not des Herres (the basic law of two cells).
is: (basic law of yang weakness) is higher than (basic law of two grids)
, but in the general law of yang weakness, individual base characters (der Friede, der Name, der Buchstabe) are mixed in. takes into account the basic law of two grids .
des Friedens instead of des Frieden
des Namens instead of des Namen
des Buchstabens instead of des Buchstaben
b. Masculine nouns that cannot be classified (also need to be memorized separately)
such as Herr cannot be classified. It does not belong to -e, nor does it belong to -ist, -at and other ending rules.
In addition there are der Mensch, der Nachbar.
The above three are extremely common and are recommended to be memorized.
c. Mixed into a neuter noun
das Herz, des Herzens, dem Herzen, das Herz
Example:
Gen. im Grunde seines Herzens Deep in his heart
Dat. Die Kinder liegen ihm am Herzen. The most important thing he cares about is his children.
Akk. Sie hat ihm das Herz gebrochen. She broke his heart.
The above is today’s content.Leave two exercises to consolidate:

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