Learn Hardcore Spanish (Latin America): Cada día avanzo un poco más cuando logro enfocarme en una sola tarea. - Every day I advance a bit more when I manage to focus on a single task.

cada día can sometimes feel a bit more individualizing, like you’re thinking of each day as a step.
todos los días can sound more general/habitual, like a routine.

In everyday conversation, most speakers would not feel a real difference here. Use whichever feels easier; both are correct in Latin American Spanish.

Why is it “avanzo” and not something like “me avanzo”? Does avanzar need a reflexive pronoun?

In this meaning (to make progress / to advance), avanzar is normally not reflexive:

Avanzo un poco más. = I make a bit more progress.
El proyecto avanza lentamente. = The project is moving forward slowly.

There is a reflexive form avanzarse, but it’s rare and usually has other, more specific uses (e.g., to move ahead of others, to rush ahead in a line, etc.).

So for “I’m making progress” or “I advance,” you should say “avanzo”, not “me avanzo”.

What does “logro” add here? Could I just say “cuando me enfoco en una sola tarea” instead?

Logro comes from lograr, which means to manage to / to succeed in / to achieve.

cuando logro enfocarme = when I manage to focus / when I’m able to focus
cuando me enfoco = when I focus (more neutral, just describing the action)

Using logro emphasizes that focusing is difficult and requires effort or success. Without logro, you lose that nuance of achievement.

So:

Cuando logro enfocarme en una sola tarea = “on the days I succeed in focusing, I make more progress.”
Cuando me enfoco en una sola tarea = “when I focus on one task, I make more progress” (more factual, less about overcoming difficulty).

Why is it “enfocarme” and not “enfocar”? Why is “enfocarse” reflexive here?

Enfocar by itself usually means to focus something (a camera, a lens, an idea):

Enfocar la cámara. = To focus the camera.
Enfocar el problema desde otro ángulo. = To approach/focus on the problem from another angle.

Enfocarse is the pronominal/reflexive form and usually means to focus oneself / to concentrate:

Necesito enfocarme en mi trabajo. = I need to focus on my work.
Nos estamos enfocando en la calidad. = We are focusing on quality.

Since in your sentence you mean “to focus (myself), to concentrate,” the reflexive form is the natural one:
logro enfocarme = “I manage to focus (myself).”

Why is the pronoun attached at the end (“enfocarme”) and not in front, like “me logro enfocar”? Are both correct?

Both of these are grammatically correct in Latin American Spanish:

cuando logro enfocarme
cuando me logro enfocar

The rules:

With a conjugated verb + infinitive, the pronoun can go:
- attached to the infinitive: logro enfocarme
- or before the conjugated verb: *me logro enfocar*
In practice:
- logro enfocarme is more common and more natural-sounding.
- me logro enfocar is understood and correct but sounds slightly more marked or less fluid in everyday speech.

What you cannot say is “logro me enfocar” — pronouns don’t go between the conjugated verb and the infinitive like that.

Why is it “enfocarme en” and not “enfocarme a” or some other preposition?

With the meaning “to focus on something”, Spanish uses “enfocarse en”:

enfocarse en una tarea = to focus on a task
enfocarse en los detalles = to focus on the details

So the standard pattern is:
enfocarse + en + [thing you are focusing on]

Using “a” (enfocarse a) is not correct in this structure. Stick with “enfocarse en”.

What’s the nuance of “una sola tarea”? Is it different from “solo una tarea” or “una tarea solamente”?

All three can be understood, but they don’t feel exactly the same:

una sola tarea
- Very common and natural.
- Emphasizes “just one, not more than one”, with a sense of exclusivity.
- Slight nuance of “I limit myself to only one task.”
solo una tarea
- Also understandable.
- Feels a bit more like “just one task”, sometimes with a nuance of “that’s not very many” depending on context.
- The position of solo can change nuance.
una tarea solamente
- Less common in this type of sentence.
- Sounds a bit more emphatic or stylistic; “one task and nothing else.”

In your sentence, “una sola tarea” is the most natural and idiomatic choice to express “a single task (only one).”

Why is the verb in the present tense (“avanzo”, “logro”) when it’s talking about something that happens repeatedly?

In Spanish, the simple present is used very often for habitual actions, similar to English:

Cada día avanzo un poco más.
= Every day I make a bit more progress.
Siempre estudio por la noche.
= I always study at night.

You could say “voy avanzando” in some contexts, but that usually emphasizes ongoing progression right now rather than a daily habit. For a regular, repeated action, present simple is the most natural:
Cada día avanzo…

Could this sentence ever use the subjunctive, like “cuando logre enfocarme” instead of “cuando logro enfocarme”?

Yes, both indicative and subjunctive are possible, but they’re used in different situations:

cuando logro enfocarme (indicative)
- Talks about a real, habitual situation in the present.
- “When I manage to focus (on the days that I do), I advance a bit more.”
cuando logre enfocarme (subjunctive)
- Points to future, hypothetical, or uncertain time.
- “When I (eventually) manage to focus, I will advance more.”
- You’d typically pair it with a future main clause:
  - Cuando logre enfocarme en una sola tarea, voy a avanzar más.

So in your original, describing a regular pattern that already happens, the indicative (“cuando logro…”) is the correct and natural choice.

Is there any difference between “enfocarme” and “concentrarme” in Latin American Spanish?

Both are widely understood and often used similarly:

enfocarme en una tarea
concentrarme en una tarea

Nuance:

Enfocarme can suggest directing your attention specifically to one thing (like a camera focusing).
Concentrarme often suggests mentally blocking out distractions to keep your mind on something.

In everyday Latin American Spanish, many people use “enfocarme en” almost interchangeably with “concentrarme en” when talking about productivity and work.

Your sentence would also sound natural as:
Cada día avanzo un poco más cuando logro concentrarme en una sola tarea.

Why is “cada día” at the beginning? Could I say “Avanzo un poco más cada día…” instead?

Yes, you can absolutely say:

Cada día avanzo un poco más…
Avanzo un poco más cada día…

Both word orders are correct and natural.

Nuance (very slight):

Starting with “Cada día” puts a bit more emphasis on the frequency/routine.
Ending with “cada día” puts a bit more emphasis on the progress and then adds “every day” as extra context.

In normal conversation, they are practically equivalent. Use whichever sounds nicer to you.

Does “un poco más” always have to go after the verb (“avanzo un poco más”) or can I move it?

In this sentence, the standard and most natural position is:

avanzo un poco más

You could technically move it in some marked or poetic ways, but in normal speech/writing you would not say:

✗ Un poco más avanzo cada día… (sounds unnatural/stylized)

So for everyday Spanish:
[verb] + un poco más is the pattern you should stick to:

Mejoro un poco más.
Aprendo un poco más.
Avanzo un poco más.