Te entiendo.

Te is the direct object pronoun meaning you in the informal singular sense.

So in Te entiendo, the structure is literally:

I understand you
= [you] I-understand

In Spanish, object pronouns like me, te, lo, la, nos, os, los, las often come before the verb.

Because entender is a stem-changing verb.

Its infinitive is entender = to understand, but in many present-tense forms the e in the stem changes to ie:

• yo entiendo = I understand
• tú entiendes = you understand
• él/ella entiende = he/she understands

But:

• nosotros entendemos
• vosotros entendéis

So entiendo is the correct yo form.

Spanish often leaves out subject pronouns when they are already clear from the verb form.

Entiendo already means I understand, so yo is not necessary.

• Te entiendo = normal, natural
• Yo te entiendo = also correct, but adds emphasis, contrast, or clarity

For example, Yo te entiendo, pero él no = I understand you, but he doesn’t.

Because Spanish object pronouns usually go before a conjugated verb.

English: I understand you
Spanish: Te entiendo

This is just a normal word-order difference between the two languages.

With a regular noun instead of a pronoun, Spanish can put it after the verb:

• Entiendo a María = I understand María

But with the pronoun, you usually say:

• La entiendo = I understand her
• Te entiendo = I understand you

Yes. Te is for tú, the informal singular you.

In Spain, if you want to be formal, you would say:

• Lo entiendo = I understand you (to a man, formal usted)
• La entiendo = I understand you (to a woman, formal usted)

For plural in Spain:

• Os entiendo = I understand you all (informal plural, vosotros/vosotras)
• Los entiendo / Las entiendo = I understand you all (formal plural, ustedes)

So Te entiendo is specifically for one person you address as tú.

Yes, there can be a slight difference, although both can mean I understand you.

• Te entiendo often means I understand what you mean / what you’re saying
• Te comprendo can sound a bit more like I understand you emotionally / I sympathise with you

In real life, though, there is overlap, and both are common.
A learner should know that entender is the most basic and very frequent verb for to understand.

A simple Spain-style pronunciation guide would be:

te en-tee-EN-do

A bit more closely:

• te = like teh
• en = like en
• tiendo has the stress on tien

The ie in entiendo sounds like a glide, roughly yen or ee-ehn blended together, depending on how detailed you want to be.

The stress falls on -tien-:

te en-TIEN-do

Yes.

• Entiendo = I understand
• Te entiendo = I understand you

If the person you understand is obvious from context, Spanish may leave out te. But if you want to clearly say I understand you, then te is useful.

For example:

• Someone explains something difficult: Entiendo = I understand
• Someone talks about their feelings: Te entiendo = I understand you

Not with a normal conjugated verb like this.
Entiendo te is not correct.

With a conjugated verb, the object pronoun goes before it:

• Te entiendo

Pronouns can attach to the end of the verb with:

• infinitives: entenderte
• gerunds: entendiéndote
• affirmative commands: entiéndeme = understand me

But with entiendo, the correct form is Te entiendo.

No, not when you use the pronoun te.

You do not say a te.

So:

• Te entiendo = correct

If you use a person’s name or noun instead, then you usually use the personal a:

• Entiendo a Ana
• Entiendo a mi hermano

But pronouns like te replace that whole object directly.

Yes, in many contexts it can.

Depending on tone and situation, Te entiendo can mean:

• I understand you
• I get you
• I know what you mean
• sometimes even I understand how you feel

So it is a very useful everyday sentence, not just a literal translation.