No quiero que mis errores en clase me desanimen.

Because no quiero que... triggers the subjunctive.

A very common pattern in Spanish is:

• querer que + subjunctive

When one person wants, doesn’t want, hopes, fears, etc. that someone/something else does something, Spanish usually uses the subjunctive in the second clause.

So:

• No quiero = I don’t want
• que mis errores... me desanimen = that my mistakes discourage me

If you used the indicative instead, it would sound wrong here.

Because the sentence has two parts with two different verbs:

1. No quiero
2. mis errores me desanimen

Spanish links those two clauses with que:

• No quiero que mis errores me desanimen.

This is very similar to English I don’t want my mistakes to discourage me, but Spanish often uses a full clause with que where English uses an infinitive.

Because the subject of desanimen is mis errores, which is plural.

So the verb must agree with mis errores:

• mi error me desanime = singular
• mis errores me desanimen = plural

Even though me appears before the verb, me is not the subject. It is the object.

Me means me and shows who is affected by the action.

• desanimar a alguien = to discourage someone
• me desanimen = discourage me

So in this sentence:

• mis errores = the thing doing the discouraging
• me = the person being discouraged

Because the subject changes.

Use an infinitive when the subject is the same:

• No quiero desanimarme. = I don’t want to discourage myself / become discouraged.

But here the subject of the second action is different:

• yo don’t want
• mis errores discourage

When the subject changes, Spanish normally uses:

• querer que + subjunctive

So:

• No quiero que mis errores me desanimen.

Here en clase most naturally means in class or during class, and it describes where those mistakes happen.

So mis errores en clase means:

• my mistakes in class
• the mistakes I make in class

It sounds natural in Spanish and clearly connects en clase with errores.

Yes, but the meaning or emphasis can shift slightly.

For example:

• No quiero que mis errores en clase me desanimen.
  Most natural: my in-class mistakes shouldn’t discourage me.

• No quiero que mis errores me desanimen en clase.
  This can sound more like the discouragement happens in class.

So the original placement is good if you want en clase to describe the errors, not the discouraging.

Because no negates the main verb quiero:

• Quiero... = I want...
• No quiero... = I don’t want...

So the whole meaning is I do not want that my mistakes in class discourage me.

The negative belongs before the conjugated verb, which is standard Spanish word order.

No. Here it is being used as a normal transitive verb:

• desanimar a alguien = to discourage someone

So:

• mis errores me desanimen = my mistakes discourage me

The reflexive form desanimarse means to become discouraged:

• No quiero desanimarme. = I don’t want to get discouraged.

Both are related, but your sentence uses the non-reflexive form.

No. After no quiero que, you need the subjunctive, so it must be:

• desanimen

not

• desaniman

A useful rule to remember is:

• quiero que / no quiero que + subjunctive

Yes, it sounds natural and correct in Spain.

It has a very standard structure and vocabulary. A speaker from Spain would understand it immediately.

You could also hear alternatives like:

• No quiero que mis errores en clase me desmotiven.
• No quiero que los errores que cometo en clase me desanimen.

But your original sentence is perfectly natural.

They are similar, but the nuance is a bit different:

• desanimar = to discourage, make someone lose heart
• desmotivar = to demotivate, make someone lose motivation

In your sentence, desanimen suggests an emotional reaction like losing confidence or feeling discouraged.
Desmotiven would focus a bit more on losing motivation to continue.

So desanimen is a very good choice if you mean I don’t want my mistakes in class to make me feel discouraged.

Yes. It is a very useful model sentence for this pattern:

• No quiero que + noun/pronoun + subjunctive

Examples:

• No quiero que llegues tarde.
• No quiero que esto me afecte.
• No quiero que mis errores me desanimen.

So this sentence is a great example of how Spanish expresses I don’t want X to happen when the second action has a different subject.