Läkaren tycker att hon är frisk.

Because Swedish usually puts the definite article on the end of the noun.

• läkare = doctor / a doctor
• läkaren = the doctor

So Läkaren tycker att hon är frisk starts with The doctor thinks ...

This is very common in Swedish:

• bok → boken = the book
• bil → bilen = the car
• läkare → läkaren = the doctor

Because Swedish often expresses the with a suffix attached to the noun instead of a separate article like English.

So English:

• the doctor

Swedish:

• läkaren

You do sometimes see a separate definite word like den/det/de, but usually that happens with adjectives:

• den snälla läkaren = the kind doctor

Without an adjective, läkaren by itself is enough.

Not exactly.

In this sentence, tycker att means something like:

• thinks
• is of the opinion that
• considers

So Läkaren tycker att hon är frisk means the doctor’s judgment/opinion is that she is healthy.

Compare:

• tycka att = to think / feel / have the opinion that
• tro att = to believe / think something is true, often with more uncertainty or assumption

Examples:

• Jag tycker att filmen är bra. = I think the movie is good.
• Jag tror att det regnar nu. = I think / believe it is raining now.

In real life, a doctor might also say something more formal, but tycker att is perfectly normal Swedish.

att here means that and introduces the clause hon är frisk.

So the sentence is built like this:

• Läkaren tycker = The doctor thinks
• att hon är frisk = that she is healthy

Very often in Swedish, att can be omitted after verbs like tycka, tro, säga, especially in speech and informal writing:

• Läkaren tycker hon är frisk.

That is also natural Swedish.

So:

• med att = a little more explicit / formal / careful
• without att = often more conversational

Because this is a statement, not a question.

Inside the att-clause, Swedish keeps normal statement word order:

• hon är frisk = she is healthy

If you turn it into a yes/no question, then the verb comes first:

• Är hon frisk? = Is she healthy?

So:

• att hon är frisk = that she is healthy
• är hon frisk? = is she healthy?

A useful extra point: if you add an adverb like inte, Swedish subordinate clauses have a different position from main clauses:

• Läkaren tycker att hon inte är frisk. = The doctor thinks that she is not healthy.

That inte placement is very important in Swedish subordinate clauses.

Because frisk is an adjective, and its form depends on what it describes.

Here it describes hon, which is singular and corresponds to common gender, so the adjective is:

• frisk

Compare:

• hon är frisk = she is healthy
• han är frisk = he is healthy
• barnet är friskt = the child is healthy
• de är friska = they are healthy

So the pattern is roughly:

• common gender singular: frisk
• neuter singular: friskt
• plural: friska

In your sentence, hon requires frisk.

Yes, it can, depending on context.

Läkaren means the doctor, but the noun itself does not tell you whether the doctor is male or female. So if the doctor is a woman, hon could in principle refer back to läkaren.

However, without context, many learners will feel the sentence is a bit ambiguous:

• it could mean the doctor thinks another woman is healthy
• or it could mean the doctor thinks she herself is healthy

If Swedish wants to make the second meaning clearer, it often adds själv:

• Läkaren tycker att hon själv är frisk. = The doctor thinks that she herself is healthy.

So yes, hon can refer to the doctor, but context matters.

Mostly here, yes, but its range is a bit broader than one single English word.

For people, frisk can mean:

• healthy
• well
• not ill
• recovered / no longer sick, depending on context

So hon är frisk could mean:

• she is healthy
• she is well
• she is not sick

In medical or everyday contexts, it often contrasts with sjuk = sick.

Also, Swedish uses frisk in some other expressions, such as:

• frisk luft = fresh air

That is a different but related meaning, so always pay attention to context.

A rough pronunciation guide is:

• läkaren ≈ LEH-ka-ren

A few helpful details:

• ä sounds somewhat like the vowel in English bed, though not exactly the same
• the k is a normal hard k sound here
• the final -en is the definite ending

And:

• frisk is roughly frisk with a short i, not like English freeze

If you are used to English spelling, the biggest thing to notice is that Swedish vowels matter a lot, so ä should be kept distinct from a and e.

Yes.

You can say:

• Läkaren tycker att hon är frisk.
• Läkaren tycker hon är frisk.

Both are correct.

The version with att may sound a little clearer or slightly more formal. The version without att is very common in everyday Swedish.

For a learner, it is often easiest to keep using att at first, because it makes the clause structure more obvious. Then later you can get more comfortable hearing and using the shorter version.