כף הרגל כואבת.

Because כף הרגל is a construct phrase (called סמיכות in Hebrew).

In a construct phrase, the first noun is linked to the second noun, and the whole phrase is made definite by the second noun. So:

• כף רגל = a foot / sole of a foot
• כף הרגל = the foot / the sole of the foot

So even though כף does not have ה־, the whole expression is definite because הרגל is definite.

Literally, it means something like the sole of the leg/foot.

The word כף can mean palm or sole, depending on context:

• כף יד = palm of the hand
• כף רגל = sole of the foot / foot

So כף הרגל is the standard Hebrew expression for the foot.

Because כף is a feminine singular noun, and the verb-like form כואבת agrees with it.

In Hebrew, present-tense forms often agree in gender and number with the subject:

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

Since the subject here is כף הרגל, and the head noun is כף (feminine singular), Hebrew uses כואבת.

Because in a construct phrase, the first noun is the grammatical head.

So in כף הרגל:

• כף is the main noun
• הרגל just completes its meaning

That means agreement is based on כף, which is feminine singular. That is why the sentence uses כואבת, not כואב.

In modern Hebrew, it functions like the present tense of the verb לכאוב (to hurt, to ache).

Historically and grammatically, Hebrew present-tense forms are related to participles, but for learners it is usually simplest to think of כואבת here as the present-tense form meaning hurts / is hurting / aches.

So:

• כף הרגל כואבת = The foot hurts / The foot is hurting

Because Hebrew normally does not use a present-tense form of to be in simple present sentences.

So where English says:

• The foot is hurting

Hebrew can simply say:

• כף הרגל כואבת

This is completely normal. In present-tense Hebrew, the equivalent of is/am/are is often omitted.

The word order is:

subject + predicate

• כף הרגל = the subject
• כואבת = the predicate

So literally:

• The foot hurts

This is a very normal Hebrew sentence pattern.

A common pronunciation is:

kaf ha-RE-gel ko-E-vet

A few notes:

• כף = kaf
• הרגל = ha-RE-gel
• כואבת = ko-E-vet

The main stress is usually:

• רֶגֶל → RE-gel
• כּוֹאֶבֶת → e-VET or ko-E-vet, depending on how carefully it is pronounced

Many learners find כואבת tricky because of the vowel sequence. It is not one smooth syllable like English kwa-; it is more clearly broken up: ko-e-vet.

The dictionary form of the verb is לכאוב (to hurt, to ache).

From that verb you get:

• כואב = hurts / hurting (masculine singular)
• כואבת = hurts / hurting (feminine singular)

So כואבת is the feminine singular present-tense form of לכאוב.

Yes, but it would usually mean The leg hurts, because רגל normally means leg.

If you specifically want to say foot, כף הרגל is clearer and more natural.

So:

• הרגל כואבת = The leg hurts
• כף הרגל כואבת = The foot hurts

A very common way is:

כף הרגל שלי כואבת = My foot hurts

Another very natural Hebrew pattern is:

כואבת לי כף הרגל
literally: The foot hurts to me

This לי structure is extremely common in Hebrew for body pain:

• כואב לי הראש = My head hurts
• כואבת לי היד = My hand hurts
• כואבת לי כף הרגל = My foot hurts

In everyday modern Hebrew, כף הרגל usually just means foot.

Literally, it can point to the sole of the foot, but in normal usage it is often the standard term for the foot as a body part. Context decides how specific it is.

So a learner should generally understand כף הרגל here as foot, unless the context clearly focuses on the sole.

Yes. Hebrew present tense often covers both ideas.

So כף הרגל כואבת can mean:

• The foot hurts
• The foot is hurting
• The foot aches

English chooses among these depending on style and context, but Hebrew uses the same form here.