אל תשכחי לקרוא גם את הסעיף האחרון וגם את הנספח לפני שאת עונה.

Because the sentence is addressed to one female.

• תשכחי = you (feminine singular) will forget / don’t forget
• תשכח = you (masculine singular) will forget / don’t forget

Hebrew changes the verb form depending on the gender and number of the person being addressed.

For comparison:

• to a man: אל תשכח
• to a woman: אל תשכחי
• to several people: אל תשכחו

So the ־י at the end helps mark the feminine singular form here.

אל is the normal word for a negative command in Hebrew.

So:

• אל תשכחי = don’t forget

By contrast, לא תשכחי usually sounds like a simple future statement:

• לא תשכחי = you will not forget

A very common Hebrew pattern is:

• אל + future form of the verb = negative command

So even though תשכחי is technically a future form, after אל it functions as don’t forget.

Because Hebrew, like English, often uses an infinitive after forget.

Compare:

• English: Don’t forget to read
• Hebrew: אל תשכחי לקרוא

Here לקרוא is the infinitive to read.

This is a very common structure:

• לשכוח לעשות משהו = to forget to do something
• אל תשכחי להביא = don’t forget to bring
• אל תשכחי להתקשר = don’t forget to call

So לקרוא is there because it is the action that must not be forgotten.

גם ... וגם means both ... and.

In this sentence:

• גם את הסעיף האחרון וגם את הנספח = both the last clause/section and the appendix

Literally, גם means also / too, but when it appears in this paired pattern, it works like English both ... and.

So:

• גם X וגם Y = both X and Y

This is a very common structure in Hebrew.

את here is the direct object marker. It does not mean you in this sentence.

Hebrew uses את before a definite direct object, especially when the noun has ה־ (the) or is otherwise definite.

So:

• את הסעיף האחרון
• את הנספח

Both nouns are definite, so את is needed.

It appears twice because there are two coordinated objects in the גם ... וגם structure:

• also the last section
• and also the appendix

English has no exact equivalent of this marker, so it often feels strange at first to English speakers.

In Hebrew, adjectives usually come after the noun.

So:

• סעיף אחרון = a last/final section
• הסעיף האחרון = the last/final section

This is different from English, where adjectives usually come before the noun.

Hebrew pattern:

• noun + adjective

Examples:

• ספר טוב = a good book
• הספר הטוב = the good book
• סעיף אחרון = a final section
• הסעיף האחרון = the final section

Because סעיף is a masculine singular noun, so the adjective must match it.

Hebrew adjectives agree with the noun in:

• gender
• number
• definiteness

So:

• סעיף = masculine singular
• therefore אחרון = masculine singular
• and because the noun is definite, the adjective is also definite: האחרון

If the noun were feminine, you would expect אחרונה instead.

For example:

• הפסקה האחרונה = the last paragraph/break
  because פסקה is feminine

Because in Hebrew, when a noun is definite, its adjective is usually definite too.

So Hebrew says:

• הסעיף האחרון

not:

• הסעיף אחרון

This is a standard rule:

• a good book = ספר טוב
• the good book = הספר הטוב

Both the noun and the adjective take definiteness.

That is why you see:

• הסעיף = the section
• האחרון = the last

שאת is made of:

• ש־ = that / when / which depending on context
• את = you (feminine singular)

So:

• לפני ש... = before ...
• לפני שאת עונה = before you answer

This is a very common Hebrew way to introduce a clause after לפני.

Compare:

• לפני הארוחה = before the meal
  here לפני is followed by a noun
• לפני שאת עונה = before you answer
  here לפני is followed by a whole clause, so ש־ is used

Yes, לפני שתעני would also be correct.

Hebrew has more than one natural way to say before you answer:

• לפני שאת עונה
• לפני שתעני

The version in your sentence uses the present form after לפני ש־, which is very common and natural in everyday Hebrew.

Very roughly:

• לפני שאת עונה feels like before you answer / before you go answering
• לפני שתעני is also normal, and can feel a little more compact or slightly more formal depending on context

So the sentence is not using a strange form; it is using one of the standard patterns Hebrew speakers use.

Yes. In writing without vowels, the masculine and feminine singular forms can look identical.

With vowel marking, they are different:

• masculine: עוֹנֶה
• feminine: עוֹנָה

But in normal everyday writing, both appear as:

• עונה

So in this sentence, עונה agrees with את because the subject is feminine singular. The gender is understood from context, even though the spelling looks the same.

This happens with some other Hebrew present-tense forms too, especially with verbs whose roots end in ה.