אם החניכיים שלך כואבות, לכי לרופא שיניים.

Here אם means if.

It introduces the condition:

אם החניכיים שלך כואבות = if your gums hurt

The same word אם can also mean whether in other sentences, but in this sentence it clearly means if.

In Hebrew, when a noun is followed by a של phrase, the noun is usually definite.

So Hebrew often says:

• החניכיים שלך = literally the gums of yours
• natural English: your gums

This is very normal Hebrew structure. Another example:

• הספר שלך = your book

So the ה־ does not make the translation weird; it is just how possession is commonly expressed.

חניכיים means gums, and it is treated as a plural noun.

That is why the sentence uses a plural form later:

• החניכיים שלך כואבות
• not החניכיים שלך כואבת

So even though English learners may think of gums as one body part, in Hebrew the word behaves grammatically as plural.

Because it agrees with החניכיים.

In Hebrew, present-tense forms like this change according to gender and number:

• כואב = masculine singular
• כואבת = feminine singular
• כואבים = masculine plural
• כואבות = feminine plural

Since חניכיים is treated here as feminine plural, the matching form is כואבות.

Hebrew usually does not use a present-tense word for to be in sentences like this.

So:

• החניכיים שלך כואבות

literally looks like:

• your gums hurting / painful

but it naturally means:

• your gums hurt
• your gums are hurting

This is completely normal Hebrew.

שלך means your / yours.

After a noun, it gives possession:

• החניכיים שלך = your gums

A useful thing to know: in normal unpointed Hebrew spelling, שלך looks the same for masculine and feminine singular. With vowels, they are different:

• שֶלְּךָ = your (to a male)
• שֶלָּךְ = your (to a female)

In this sentence, the later word לכי shows that the person being addressed is female.

לכי is the imperative form of go! when speaking to one female.

Hebrew imperatives change for gender and number:

• לך = go! (to one male)
• לכי = go! (to one female)
• לכו = go! (to more than one person)

So this sentence is addressed to a woman or girl.

If you were speaking to a man, you would say:

אם החניכיים שלך כואבות, לך לרופא שיניים.

It literally means doctor of teeth, i.e. dentist.

Parts:

• רופא = doctor
• שיניים = teeth

This is the normal everyday Hebrew expression for dentist.

If you specifically wanted to say female dentist, you could say רופאת שיניים.

It can be understood either way, depending on context.

The prefix ל־ means to, so לרופא שיניים means to a dentist / to the dentist.

In unpointed Hebrew spelling, לרופא can represent either:

• לרופא = to a doctor
• לרופא = to the doctor

The spelling is the same; pronunciation and context tell you which one is meant.

In a sentence like this, which gives general advice, English might say either:

• go to a dentist
• go to the dentist

Both fit the Hebrew well.