Learn Hardcore German: Unsere Erzieherin ist ehrgeizig und plant jede Woche neue Spiele für die Kinder. - Our preschool teacher is ambitious and plans new games for the children every week.

Erzieherin is feminine, singular, nominative (she is the subject of the sentence).
The correct ending for a feminine nominative noun after a possessive like unser is -e.

So you get:

unsere Erzieherin = our (female) educator / nursery teacher
If it were masculine: unser Erzieher (no -e in the masculine nominative singular).

What exactly does Erzieherin mean, and is there a masculine form?

Erzieherin is a profession: it usually refers to a female preschool teacher, nursery school teacher, or childcare worker (depending on the country/context).

The base word is Erzieher (educator / childcare worker).
The -in ending makes it explicitly female: Erzieherin.
The masculine form is der Erzieher.
The feminine form is die Erzieherin.

In many contexts, Erzieher/Erzieherin is used specifically for people working in Kindergarten, preschools, or childcare, not for teachers in regular schools (those are usually Lehrer/Lehrerin).

Why does ehrgeizig have no ending? Shouldn’t it be ehrgeizige?

In the sentence, ehrgeizig is used after the verb sein (ist), so it’s a predicate adjective:

Unsere Erzieherin ist ehrgeizig. = Our educator is ambitious.

In German, adjectives after “sein” (to be) (or similar verbs like werden, bleiben) normally don’t take endings:

Sie ist nett. (not nette)
Er bleibt ruhig. (not ruhige)

Adjective endings (-e, -en, -em, -er...) mainly appear before a noun:

eine ehrgeizige Erzieherin (an ambitious educator)
der ehrgeizige Mann (the ambitious man)

Why is there no comma before und in ist ehrgeizig und plant …?

In German, when two verbs share the same subject and are simply joined by und, you normally don’t put a comma:

Unsere Erzieherin ist ehrgeizig und plant jede Woche neue Spiele …

Both verbs (ist, plant) have the same subject (Unsere Erzieherin), so no comma is required.

You would use a comma if you were joining two independent clauses, each with its own subject (and often its own verb):

Unsere Erzieherin ist ehrgeizig, und sie plant jede Woche neue Spiele.

Here you have:

Clause 1: Unsere Erzieherin ist ehrgeizig
Clause 2: sie plant jede Woche neue Spiele

Why is it jede Woche and not jeden Woche or jede Wochen?

Three things are going on:

Gender of “Woche”
- Woche is feminine: die Woche.
Form of “jede”
- For feminine singular nominative or accusative, you use jede:
  - jede Woche (every week)
- jeden is for masculine accusative singular or dative plural, so jeden Woche is ungrammatical here.
Why singular, not plural?
In expressions of regular time/frequency, German usually uses the singular:
- jede Woche – every week
- jeden Tag – every day
- jedes Jahr – every year

So the correct form is jede Woche, feminine singular, used as an adverbial of time.

What case is jede Woche in, and why?

Grammatically, jede Woche is in the accusative singular, because:

Woche is feminine → die Woche
Accusative feminine singular → jede Woche

However, in practice, native speakers don’t think “Oh, that’s the accusative now”; this is just the typical form used for time expressions:

jeden Tag (masc. acc.)
jede Woche (fem. acc.)
jedes Jahr (neut. acc.)

These are accusative adverbials of time describing how often / when something happens.

Why is it neue Spiele and not neuen Spiele or neue Spielen?

Break it down:

What is “neue Spiele” in the sentence?
- It’s the direct object of plant:
  (Sie) plant neue Spiele. → She plans new games.
Case and number
- Direct object → accusative.
- Spiele is plural of Spiel (game).
Adjective ending
There is no article directly before neue Spiele (no die, keine, etc.).
In plural accusative with no article, adjective endings are -e:
- Sie kauft neue Bücher.
- Er sucht interessante Spiele.

So we get:

neue Spiele (correct: plural accusative, no article)
neuen Spiele would need a definite or possessive article, e.g. die neuen Spiele.
Spielen is a verb (to play) or dative plural (mit den Spielen), not correct here as a direct object.

Why is it für die Kinder and not something like für den Kindern?

The preposition für always takes the accusative case.

das Kind → die Kinder (plural)
Nominative plural: die Kinder
Accusative plural: also die Kinder (same form)

So:

für das Kind – for the child (singular accusative)
für die Kinder – for the children (plural accusative)

Für den Kindern would mix accusative (für) with a dative-like ending (den Kindern) and is incorrect.

Can I move für die Kinder to another place in the sentence?

Yes. German word order is fairly flexible with adverbials (time, manner, place, purpose) and prepositional phrases.

Your original sentence:

Unsere Erzieherin ist ehrgeizig und plant jede Woche neue Spiele für die Kinder.

Other natural options:

Unsere Erzieherin ist ehrgeizig und plant für die Kinder jede Woche neue Spiele.
Unsere Erzieherin ist ehrgeizig und plant jede Woche für die Kinder neue Spiele.

All are grammatically correct. The end position (… neue Spiele für die Kinder) feels very natural because German often puts prepositional complements and detail toward the end of the clause.

How would the sentence change if the educator were male?

You would change the noun and the possessive ending:

Feminine: Unsere Erzieherin ist ehrgeizig und plant jede Woche neue Spiele für die Kinder.
Masculine: Unser Erzieher ist ehrgeizig und plant jede Woche neue Spiele für die Kinder.

Changes:

unsere Erzieherin → unser Erzieher
- Erzieher is masculine, so the nominative with unser is just unser Erzieher (no final -e).
The rest of the sentence stays the same.

Does plant only mean “plans,” or can it also mean “is planning” like in English?

German doesn’t have a separate continuous form like English (is planning). The simple present covers both:

Sie plant neue Spiele.
→ She plans new games.
→ She is planning new games.

Context decides whether it sounds more like a general habit or a current ongoing action.

In your full sentence:

Unsere Erzieherin ist ehrgeizig und plant jede Woche neue Spiele für die Kinder.

This clearly describes a regular habit (she does this every week), but grammatically it’s just present tense, which can correspond to both “plans” and “is planning” in English.

Is ehrgeizig usually positive or negative?

Ehrgeizig literally means “ambitious” and, like in English, it can be:

Positive, especially in contexts like school, work, or sports:
motivated, driven, wants to achieve good results
Negative, if it implies being too focused on success or status at the expense of others:
overly ambitious, ruthless, obsessed with achievement

In your sentence, with a preschool educator planning new games for the children, ehrgeizig is very likely meant in a positive sense: she’s motivated, creative, and puts effort into her work.