Det är lättare att andas när halsen inte är så torr.

Here det is a dummy subject, like English it in It is easier to breathe.

It does not refer to a specific thing. Swedish often uses det är to make general statements about what something is like:

• Det är svårt att förstå. = It is hard to understand.
• Det är kallt ute. = It is cold outside.

So Det är lättare att andas means It is easier to breathe.

Lättare is the comparative form of lätt:

• lätt = easy
• lättare = easier
• lättast = easiest

So the sentence means it is easier to breathe, not just it is easy to breathe.

Even if the thing being compared is not said directly, Swedish can still use the comparative when the comparison is understood from context. Here the idea is:

• easier to breathe when the throat is not so dry
• than when it is dry

Andas is the verb to breathe, and att is the infinitive marker, like English to.

So:

• andas = breathe
• att andas = to breathe

After expressions like det är lätt/lättare/svårt att..., Swedish normally uses att + infinitive:

• Det är lätt att läsa. = It is easy to read.
• Det är svårt att sova. = It is hard to sleep.

So Det är lättare att andas is a very standard structure.

Here när means when.

The clause när halsen inte är så torr means when the throat is not so dry.

In sentences like this, när is often used for a situation that is generally true or expected:

• It is easier to breathe when the throat is not so dry.

If you used om, that would be more like if:

• Det är lättare att andas om halsen inte är så torr.

That is also possible in many contexts, but när sounds more like a general factual relationship, while om sounds more conditional.

Halsen is the definite form: the throat.

In Swedish, body parts are often expressed with the definite form where English might prefer a possessive like my throat or your throat, especially when it is obvious whose body part is meant.

So Swedish often says things like:

• Jag tvättar händerna. = I wash my hands.
• Hon har ont i ryggen. = She has pain in her back.

So halsen here is very natural. It means the throat, but in English we might understand it as your throat or the throat depending on context.

Because när halsen inte är så torr is a subordinate clause.

In Swedish subordinate clauses, sentence adverbs like inte usually come before the finite verb:

• Main clause: Halsen är inte torr.
• Subordinate clause: ...när halsen inte är torr.

This is one of the most important word-order patterns in Swedish.

So:

• Halsen är inte så torr. = main clause
• när halsen inte är så torr = subordinate clause

Here så means something like so or that in a degree sense.

So inte så torr means:

• not so dry
• not that dry

It softens the statement a little. Compare:

• Halsen är inte torr. = The throat is not dry.
• Halsen är inte så torr. = The throat is not so dry / not that dry.

This often sounds more natural when talking about degree rather than making a completely absolute statement.

Because torr is agreeing with halsen, which is a common-gender singular noun (en hals).

When an adjective is used after är as a predicative adjective, it still agrees with the noun:

• en hals → halsen är torr
• ett sår → såret är torrt
• halsarna → halsarna är torra

So:

• halsen = common gender singular
• therefore torr

No, andas is normally just the verb to breathe. It does not need sig.

Examples:

• Jag andas. = I am breathing.
• Det är svårt att andas. = It is hard to breathe.

Some Swedish verbs are reflexive, but andas is not normally treated that way in ordinary use.

Yes, that is grammatically correct.

Using min hals makes it explicitly my throat. That can be useful if you really want to emphasize whose throat you mean.

But in many everyday situations, Swedish prefers the simpler and more idiomatic halsen, especially with body parts, when the owner is obvious from context.

So both are possible, but halsen often sounds more natural.

It has two parts:

1. Det är lättare att andas
   = main clause
   = It is easier to breathe

2. när halsen inte är så torr
   = subordinate clause
   = when the throat is not so dry

So the full structure is:

• main clause + subordinate clause

A useful thing to notice is that the subordinate clause is introduced by när, and that is why the word order becomes inte är.

Yes. It sounds very natural as a general truth or general observation.

It is not necessarily about one exact moment right now. It can mean something like:

• in general, breathing is easier when the throat is less dry

That is one reason när works well here: it can introduce a general situation, not just a single event in time.