German language
Noun inflection: German nouns inflect by case, gender, and number:

four cases: nominative, accusative, genitive, and dative.
three genders: masculine, feminine, and neuter. Word endings sometimes reveal grammatical gender: for instance, nouns ending in -ung (-ing), -schaft (-ship), -keit or heit (-hood, -ness) are feminine, nouns ending in -chen or -lein (diminutive forms) are neuter and nouns ending in -ismus (-ism) are masculine. Others are more variable, sometimes depending on the region in which the language is spoken. And some endings are not restricted to one gender, for example: -er (-er), such as Feier (feminine), celebration, party; Arbeiter (masculine), labourer; and Gewitter (neuter), thunderstorm.
two numbers: singular and plural.
This degree of inflection is considerably less than in Old High German and other old Indo-European languages such as Latin, Ancient Greek, and Sanskrit, and it is also somewhat less than, for instance, Old English, modern Icelandic, or Russian. The three genders have collapsed in the plural. With four cases and three genders plus plural, there are 16 permutations of case and gender/number of the article (not the nouns), but there are only six forms of the definite article, which together cover all 16 permutations. In nouns, inflection for case is required in the singular for strong masculine and neuter nouns only in the genitive and in the dative (only in fixed or archaic expressions), and even this is losing ground to substitutes in informal speech. Weak masculine nouns share a common case ending for genitive, dative, and accusative in the singular. Feminine nouns are not declined in the singular. The plural has an inflection for the dative. In total, seven inflectional endings (not counting plural markers) exist in German: -s, -es, -n, -ns, -en, -ens, -e.

Compounding: Like the other Germanic languages, German forms noun compounds in which the first noun modifies the category given by the second: Hundehütte ("dog hut"; specifically: "dog kennel"). Unlike English, whose newer compounds or combinations of longer nouns are often written "open" with separating spaces, German (like some other Germanic languages) nearly always uses the "closed" form without spaces, for example: Baumhaus ("tree house"). Like English, German allows arbitrarily long compounds in theory (see also English compounds). The longest German word verified to be actually in (albeit very limited) use is Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz, which, literally translated, is "beef labelling supervision duties assignment law" [from Rind (cattle), Fleisch (meat), Etikettierung(s) (labelling), Überwachung(s) (supervision), Aufgaben (duties), Übertragung(s) (assignment), Gesetz (law)]. However, examples like this are perceived by native speakers as excessively bureaucratic, stylistically awkward, or even satirical. On the other hand, even this compound could be expanded by any native speaker.

Verb inflection: The inflection of standard German verbs includes:

Two main conjugation classes: weak and strong (as in English). Additionally, there is a third class, known as mixed verbs, whose conjugation combines features of both the strong and weak patterns.
Three persons: first, second and third.
Two numbers: singular and plural.
Three moods: indicative, imperative and subjunctive (in addition to infinitive).
Two voices: active and passive. The passive voice uses auxiliary verbs and is divisible into static and dynamic. Static forms show a constant state and use the verb to be (sein). Dynamic forms show an action and use the verb to become (werden).
Two tenses without auxiliary verbs (present and preterite) and four tenses constructed with auxiliary verbs (perfect, pluperfect, future and future perfect).
The distinction between grammatical aspects is rendered by combined use of the subjunctive or preterite marking so the plain indicative voice uses neither of those two markers; the subjunctive by itself often conveys reported speech; subjunctive plus preterite marks the conditional state; and the preterite alone shows either plain indicative (in the past), or functions as a (literal) alternative for either reported speech or the conditional state of the verb, when necessary for clarity.
The distinction between perfect and progressive aspect is and has, at every stage of development, been a productive category of the older language and in nearly all documented dialects, but strangely enough it is now rigorously excluded from written usage in its present normalised form.
Disambiguation of completed vs. uncompleted forms is widely observed and regularly generated by common prefixes (blicken [to look], erblicken [to see – unrelated form: sehen]).

Verb prefixes: The meaning of basic verbs can be expanded and sometimes radically changed through the use of a number of prefixes. Some prefixes have a specific meaning; the prefix zer- refers to destruction, as in zerreißen (to tear apart), zerbrechen (to break apart), zerschneiden (to cut apart). Other prefixes have only the vaguest meaning in themselves; ver- is found in a number of verbs with a large variety of meanings, as in versuchen (to try) from suchen (to seek), vernehmen (to interrogate) from nehmen (to take), verteilen (to distribute) from teilen (to share), verstehen (to understand) from stehen (to stand).
Other examples include the following:
haften (to stick), verhaften (to detain); kaufen (to buy), verkaufen (to sell); hören (to hear), aufhören (to cease); fahren (to drive), erfahren (to experience).
Many German verbs have a separable prefix, often with an adverbial function. In finite verb forms, it is split off and moved to the end of the clause and is hence considered by some to be a "resultative particle". For example, mitgehen, meaning "to go along", would be split, giving Gehen Sie mit? (Literal: "Go you with?"; Idiomatic: "Are you going along?").
Indeed, several parenthetical clauses may occur between the prefix of a finite verb and its complement (ankommen = to arrive, er kam an = he arrived, er ist angekommen = he has arrived):

Er kam am Freitagabend nach einem harten Arbeitstag und dem üblichen Ärger, der ihn schon seit Jahren immer wieder an seinem Arbeitsplatz plagt, mit fraglicher Freude auf ein Mahl, das seine Frau ihm, wie er hoffte, bereits aufgetischt hatte, endlich zu Hause an.
A selectively literal translation of this example to illustrate the point might look like this:

He "came" on Friday evening, after a hard day at work and the usual annoyances that had time and again been troubling him for years now at his workplace, with questionable joy, to a meal which, as he hoped, his wife had already put on the table, finally home "to".

Word order: German word order is generally with the V2 word order restriction and also with the SOV word order restriction for main clauses. For yes–no questions, exclamations, and wishes, the finite verb always has the first position. In subordinate clauses, all verb forms occur at the very end.
German requires a verbal element (main verb, modal verb or auxiliary verb as finite verb) to appear second in the sentence. The verb is preceded by the topic of the sentence. The element in focus appears at the end of the sentence. For a sentence without an auxiliary, these are several possibilities:

Der alte Mann gab mir gestern das Buch. (The old man gave me yesterday the book; normal order)
Das Buch gab mir gestern der alte Mann. (The book gave [to] me yesterday the old man)
Das Buch gab der alte Mann mir gestern. (The book gave the old man [to] me yesterday)
Das Buch gab mir der alte Mann gestern. (The book gave [to] me the old man yesterday)
Gestern gab mir der alte Mann das Buch. (Yesterday gave [to] me the old man the book, normal order)
Mir gab der alte Mann das Buch gestern. ([To] me gave the old man the book yesterday (entailing: as for someone else, it was another date))
The position of a noun in a German sentence has no bearing on its being a subject, an object or another argument. In a declarative sentence in English, if the subject does not occur before the predicate, the sentence could well be misunderstood.
However, German's flexible word order allows one to emphasise specific words:
Normal word order:

Der Direktor betrat gestern um 10 Uhr mit einem Schirm in der Hand sein Büro.
The manager entered yesterday at 10 o'clock with an umbrella in the hand his office.
Second variant in normal word order:

Der Direktor betrat sein Büro gestern um 10 Uhr mit einem Schirm in der Hand.
The manager entered his office yesterday at 10 o'clock with an umbrella in the hand.
This variant accentuates the time specification and that he carried an umbrella.
Object in front:

Sein Büro betrat der Direktor gestern um 10 Uhr mit einem Schirm in der Hand.