Si el limón está muy agrio, pongo media cucharadita de miel y se arregla.

Because this is a real or possible condition, not a hypothetical one.

In Spanish, si is normally followed by the indicative when you are talking about something that can really happen:

• Si llueve, me quedo en casa.
• Si tengo tiempo, te llamo.

So here:

• Si el limón está muy agrio... = If the lemon is very sour...

You do not use the subjunctive after si in this kind of sentence.

Because estar is used for a state or condition at that moment, while ser is more for an essential characteristic.

Here, the idea is that the lemon tastes very sour in this particular case, so está sounds natural.

• está agrio = it is sour / it tastes sour right now
• es agrio = it is sour by nature, or sour as a defining trait

With food and taste, Spanish often uses estar when describing how something turns out or tastes in a given situation.

Here agrio means sour.

It is commonly used for taste:

• un limón agrio = a sour lemon
• sabe agrio = it tastes sour

A learner may also know ácido, but agrio is the more natural everyday word for the taste of something like lemon, wine, or milk that has gone sour.

So in this sentence, muy agrio is simply very sour.

Spanish often uses the definite article where English would not.

Here el limón can refer to:

• the lemon in a specific situation, or
• lemon as the thing being used

Spanish is much more comfortable than English with using el/la/los/las in general statements or recipe-style comments.

So Si el limón está muy agrio... sounds natural, even if English might sometimes say If the lemon is too sour or even just If the lemon tastes too sour.

Because the sentence describes a habitual solution or a general rule.

This kind of present tense is very common in Spanish:

• Si hace frío, me pongo un abrigo.
• Si está muy salado, añado agua.

So:

• pongo = I add / I put
• se arregla = it gets fixed / that solves it

It does not necessarily mean this is happening right now. It can mean:

• this is what I do in that situation
• that’s how it is solved

Because Spanish usually drops subject pronouns when they are not needed.

The verb pongo already tells you the subject is I:

• pongo = I put / I add

So yo pongo is possible, but unnecessary unless you want emphasis or contrast:

• Yo pongo miel, pero ella pone azúcar.

In a normal sentence, just pongo is the most natural choice.

Because media agrees with the noun cucharadita, which is feminine.

• medio limón = half a lemon
• media cucharadita = half a teaspoon

So the word changes form:

• medio for masculine singular
• media for feminine singular

This is a very common agreement pattern in Spanish.

Cucharadita literally means small spoonful and in practice usually means teaspoon.

It comes from:

• cuchara = spoon
• -ita = diminutive ending, giving the idea of something small

So:

• cucharada = tablespoon / spoonful
• cucharadita = teaspoon / small spoonful

In this sentence, media cucharadita de miel means half a teaspoon of honey.

Because Spanish often uses de to show what something contains.

So:

• una cucharadita de azúcar = a teaspoon of sugar
• media cucharadita de miel = half a teaspoon of honey

This is the standard structure for amounts:

• cantidad + de + noun

Literally, arreglar means to fix or to sort out.

Here, se arregla means something like:

• it fixes itself
• that solves it
• it comes right

This use of se is not really a normal reflexive in the sense of someone doing something to themselves. It is closer to a middle/passive-like use, where the focus is on the result rather than on who does the fixing.

So:

• lo arreglo = I fix it
• se arregla = it gets fixed / it sorts itself out

In this sentence, se arregla sounds natural because the honey solves the problem.

It does not refer to a specific person. It helps create the idea that the problem is resolved.

You can think of it as referring loosely to the situation:

• the taste problem
• the lemon mixture
• the drink/food being prepared

Spanish often uses se this way to make the sentence sound less focused on the person doing the action and more on the outcome.

So y se arregla is basically:

• and that fixes it
• and it turns out fine
• and the problem is solved

Yes. That is often the best way to understand it.

A very literal breakdown is:

• y = and
• se arregla = it gets fixed / it fixes itself

But in natural English, you would often say:

• and that fixes it
• and it sorts it out
• and it comes out fine

So the literal wording is useful for grammar, but the natural meaning is more important here.

Yes, but it would change the feel.

The original sentence uses the present tense for a general habit or usual solution:

• Si el limón está muy agrio, pongo...

If you say:

• Si el limón está muy agrio, pondré media cucharadita de miel...

that sounds more like in that future situation, I will add...

So both are possible, but the original is better if the speaker means:

• this is what I normally do
• this is my usual remedy

Because the conditional clause comes first.

In Spanish, when the si clause comes before the main clause, it is normally separated by a comma:

• Si quieres, vamos.
• Si hace calor, abro la ventana.

So:

• Si el limón está muy agrio, pongo media cucharadita de miel y se arregla.

If the order were reversed, the comma would usually disappear:

• Pongo media cucharadita de miel si el limón está muy agrio.

Grammatically it is and, but in context it also carries the idea of result or next step.

So:

• pongo media cucharadita de miel y se arregla

literally = I add half a teaspoon of honey and it gets fixed

But in natural English, you might understand it as:

• I add half a teaspoon of honey, and then it’s fine
• I add half a teaspoon of honey, and that solves it

So y is still and, but the sequence makes it feel a bit like and then / and as a result.

Yes, depending on context.

Literally, el limón means the lemon, but in everyday speech Spanish sometimes uses the ingredient name in a broader way. In a cooking or drinks context, it could refer to:

• the lemon itself
• the juice from the lemon
• the lemon taste in the mixture

That is one reason se arregla works well: the speaker is focused on correcting the taste, not on describing the object very precisely.

Yes, it sounds very natural.

Several things make it sound conversational and idiomatic:

• omission of yo
• present tense for a usual action
• media cucharadita
• se arregla as a casual way to mean that solves it

It has the feel of someone informally explaining a kitchen trick or a personal habit.