אם את לא זוכרת את הכלל, תכתבי לעצמך דוגמה במחברת ותקראי אותה בערב.

They are not the same word, even though they are spelled the same.

• The first את means you and is the feminine singular subject pronoun.
• The second את is the direct object marker. It has no real English equivalent.

Hebrew uses the object-marker את before a definite direct object, so:

• את הכלל = the rule as a specific object
• but just דוגמה = an example, which is indefinite, so there is no את

So the pattern is:

• זוכרת את הכלל = remember the rule
• תכתבי דוגמה = write an example

If the noun were definite, you would use את there too:

• תכתבי את הדוגמה = write the example

Because in modern Hebrew, the verb to be is usually omitted in the present tense.

So את לא זוכרת literally looks more like:

• you not remembering

But in natural English, that becomes you don't remember.

This is very normal in Hebrew:

• אני עייף = I am tired
• היא בבית = she is at home
• את לא זוכרת = you do not remember

In past and future, Hebrew does use forms of היה:

• היית = you were
• תהיי = you will be

Because the sentence is addressed to one female person.

Hebrew verbs and related forms often agree with the subject in gender and number. Here:

• את = you, feminine singular
• זוכרת = remembering, feminine singular

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

אם אתה לא זוכר את הכלל, תכתוב לעצמך דוגמה במחברת ותקרא אותה בערב.

Key changes:

• את → אתה
• זוכרת → זוכר
• תכתבי → תכתוב
• תקראי → תקרא

Because אם את לא זוכרת presents the condition as a current or general situation: if you don't remember.

In Hebrew, after אם, the present tense is often used when the speaker means something like:

• if you don’t remember
• if you’re not sure
• if you don’t know

So אם את לא זוכרת את הכלל is very natural.

You could also say אם לא תזכרי, but that sounds a bit more specifically future-oriented, closer to:

• if you won’t remember
• if you happen not to remember later

English often uses the same wording for both, but Hebrew can make a slightly different choice.

Because in the present tense, the form זוכרת shows gender and number, but not clearly person by itself. It could mean something like:

• I remember
• you remember
• she remembers

depending on context.

So Hebrew often includes the subject pronoun in present-tense sentences:

• את לא זוכרת

But in the future tense, the verb itself already tells you the person:

• תכתבי = you will write / write, feminine singular
• תקראי = you will read / read, feminine singular

So the pronoun is usually unnecessary there unless you want emphasis:

• את תכתבי, לא היא = you will write, not her

Because in modern Hebrew, the second-person future is very commonly used to give commands, instructions, or advice.

So although תכתבי literally looks like you will write, in context it often means:

• write
• you should write
• go ahead and write

The same is true for תקראי.

This is especially common in everyday spoken Hebrew. After a condition like אם..., it sounds very natural:

• אם את לא זוכרת..., תכתבי... ותקראי...

In English, we often use the imperative directly, but Hebrew often prefers these future forms in ordinary speech.

Yes. They are grammatically correct:

אם את לא זוכרת את הכלל, כתבי לעצמך דוגמה במחברת וקראי אותה בערב.

But in modern everyday Hebrew, that usually sounds more:

• formal
• literary
• direct
• instruction-manual-like

In normal conversation, many speakers prefer the future forms:

• תכתבי
• תקראי

So both are correct, but תכתבי / תקראי usually sound more natural in casual modern speech.

לעצמך means something like for yourself or to yourself.

It is built from:

• ל־ = to / for
• עצמך = yourself

So:

• תכתבי לעצמך דוגמה = write yourself an example / write an example for yourself

Here it suggests writing it as a personal note or aid, not for someone else.

A useful comparison:

• כתבתי לעצמי = I wrote myself / for myself
• כתבי לעצמך = write for yourself

אותה means it here, and it refers to דוגמה.

The noun דוגמה is feminine, so the object pronoun must also be feminine:

• דוגמה → אותה

That is why the sentence says:

• ותקראי אותה בערב = and read it in the evening

If the noun were masculine, Hebrew would use אותו instead:

• ספר → אותו

So Hebrew object pronouns agree with the noun’s gender and number.

The prefix ב־ usually means in, at, or sometimes on, depending on context.

So here:

• במחברת = in a notebook / in the notebook
• בערב = in the evening / in the evening time

A useful thing to know: when ב־ combines with the definite article ה־, they merge.

So:

• ב + הערב becomes בערב

In unpointed Hebrew writing, במחברת can be a little ambiguous, because the spelling may represent either:

• in a notebook
• in the notebook

Usually context or pronunciation makes that clear.

Because Hebrew often does not need an explicit word for then in an if ... then ... sentence.

So:

• אם את לא זוכרת את הכלל, תכתבי... already naturally means
• If you don’t remember the rule, then write...

Hebrew can add אז for then, but it is often unnecessary:

• אם את לא זוכרת את הכלל, אז תכתבי לעצמך דוגמה...

That version is possible, but the original sentence is completely normal without it.