После практики я понял, что хочу работать учителем.

Because после requires the genitive case.

• Dictionary form: практика
• Genitive singular: практики

So:

• после практики = after the practice / after the internship / after practical training

This is a very common pattern in Russian:

• после урока = after the lesson
• после работы = after work
• после университета = after university

So the form практики is there because of the preposition после.

In this sentence, практика usually means something like:

• teaching practice
• practical training
• an internship
• a practicum

The exact translation depends on context. For example, if the speaker is studying education, после практики could mean after my teaching placement or after my student teaching.

So although практика can sometimes look like English practice, here it often means a period of real-world training, not just repeated exercise.

Понял is the past tense, masculine singular form of the verb понять (to understand / to realize).

So:

• я понял = I realized / I understood said by a male speaker
• я поняла = the same thing said by a female speaker

Russian past tense agrees with gender in the singular:

• masculine: понял
• feminine: поняла
• neuter: поняло
• plural: поняли

So if a woman says this sentence, it would be:

После практики я поняла, что хочу работать учителем.

Что introduces a subordinate clause, similar to that in English.

So:

• я понял = I realized
• что хочу работать учителем = that I want to work as a teacher

Together:

• я понял, что... = I realized that...

In English, that is often optional:

• I realized that I want...
• I realized I want...

In Russian, что is normally used in this kind of sentence.

Both are possible:

• я понял, что хочу работать учителем
• я понял, что я хочу работать учителем

Russian often omits the subject pronoun when it is clear from the verb ending or from context. Since хочу already clearly means I want, the second я is unnecessary.

Including я can add emphasis or contrast, but leaving it out sounds very natural and common.

So this sentence is perfectly normal without the second я.

This is a standard Russian pattern:

• хотеть + infinitive = to want to do something

So:

• хочу работать = I want to work
• хочу учиться = I want to study
• хочу поехать = I want to go

Here:

• хочу = I want
• работать = to work

So the structure is just want + infinitive, like in English.

Because after работать when you mean to work as (something), Russian usually uses the instrumental case.

• dictionary form: учитель = teacher
• instrumental singular: учителем

So:

• работать учителем = to work as a teacher

This is a very important pattern:

• работать врачом = to work as a doctor
• работать инженером = to work as an engineer
• работать переводчиком = to work as a translator

So учителем is not random—it is the expected case after работать in this meaning.

Yes. In this sentence, учителем is best understood as as a teacher.

Russian often expresses job roles with the instrumental case instead of using a separate word for as:

• работать учителем = work as a teacher
• работать врачом = work as a doctor

So even though there is no separate Russian word here meaning as, the instrumental ending does that job.

Yes, Russian word order is flexible, but this version is natural and neutral.

This sentence is structured as:

• После практики = time/background
• я понял = main action
• что хочу работать учителем = content of the realization

A different word order is possible, for example:

• Я понял после практики, что хочу работать учителем.

That also works, but it shifts the emphasis slightly. Starting with После практики naturally sets the scene first: After the internship/practical training...

So the given order is a common, natural way to present the information.

Both are possible, but realized is usually better here.

• понять can mean to understand
• but in sentences like this, it often means to realize

So:

• После практики я понял, что хочу работать учителем.
• After my practical training, I realized that I want to work as a teacher.

Why realized works better: The sentence describes coming to a conclusion or discovering something about oneself, not just understanding information. That idea is usually expressed more naturally in English by realized.

Понять is perfective, while понимать is imperfective.

Here we get the past form понял from понять.

Why perfective? Because the sentence describes a completed moment of realization:

• after the practical training, the speaker came to a realization

That is exactly the kind of situation where Russian often uses the perfective aspect.

Compare:

• я понимал = I understood / I was understanding / I used to understand
• я понял = I understood / I realized at a particular moment

In this sentence, the speaker is talking about a specific result: I came to realize. So понял is the natural choice.

Yes. If the speaker is female, поняла would change, but учителем can still stay the same if she means teacher in a general professional sense.

So a female speaker could say:

• После практики я поняла, что хочу работать учителем.

In modern Russian, women may also sometimes use feminine job nouns in some contexts, but after работать the masculine profession word is still very common and normal, especially for many occupations.

So the main required change for a female speaker is:

• понял → поняла

Yes. Учитель usually means a schoolteacher. If you mean a university teacher or lecturer, Russian often uses other words, such as:

• преподаватель = teacher/instructor, often in colleges, universities, or courses

So:

• работать учителем usually suggests working in a school
• работать преподавателем suggests teaching in a broader or often more advanced educational setting

That is why the exact nuance of учителем may matter depending on context.