אם תהיי פנויה מחר, נוכל לדבר על מה שקרה היום ולבדוק מה יהיה הכי טוב לעשות.

Because the sentence is addressed to one woman.

In Hebrew, both the verb and the adjective have to agree with the person being addressed:

• תהיי = you will be / you are (future, feminine singular)
• פנויה = free / available (feminine singular)

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

• אם תהיה פנוי מחר...

If you were speaking to more than one person:

• אם תהיו פנויים מחר...

That is the standard modern spelling of this form.

תהיי is the 2nd person feminine singular future form of להיות (to be). Learners often find this spelling unusual, but it is the normal written form in modern Hebrew.

The most important thing to remember is simply:

• תהיה = to a man
• תהיי = to a woman

Here it means available / free, as in not busy.

So אם תהיי פנויה מחר means something like:

• If you’re free tomorrow
• If you’re available tomorrow

It is true that פנוי / פנויה can sometimes mean single or available romantically, but that is not the meaning here. The context makes it clear that this is about someone’s schedule.

Because in Hebrew, when you talk about a real future condition, you normally use the future tense after אם.

So Hebrew says:

• אם תהיי פנויה מחר, נוכל...

Literally, that is closer to:

• If you will be free tomorrow, we will be able...

But natural English usually says:

• If you’re free tomorrow, we can...

So this is a major difference between Hebrew and English:

• Hebrew: future + future
• English: present + future/modal

Another example:

• אם תבוא, נדבר = If you come, we’ll talk

Grammatically, נוכל is the future tense of יכול (to be able / can), so its basic meaning is:

• we will be able to

But in real English translation, the best wording depends on context. In this sentence, it can naturally mean:

• we can
• we could
• we’ll be able to

Here it sounds like a suggestion or a practical possibility, so English often uses we can or we could.

Because the Hebrew verb לדבר usually takes על when you mean to talk about something.

So:

• לדבר על משהו = to talk about something

In this sentence:

• לדבר על מה שקרה היום = to talk about what happened today

You cannot usually drop על here, because לדבר and על go together when introducing the topic of conversation.

This is a very common Hebrew structure:

• מה ש־... = what ... / that which ...

So:

• מה שקרה = what happened
• literally: the thing that happened

By contrast:

• מה קרה? = What happened?
  This is a direct question.

So the difference is:

• מה קרה? = a question
• מה שקרה = a noun-like phrase meaning what happened

In your sentence, it is not asking a question. It is referring to the event:

• לדבר על מה שקרה היום = to talk about what happened today

Literally, yes, לבדוק means to check / examine.

But in this sentence it is more natural in English as:

• to see
• to look into
• to figure out
• to consider

So:

• ולבדוק מה יהיה הכי טוב לעשות

does not mean physically checking something. It means something like:

• and see what would be best to do
• and figure out the best thing to do

Word by word, it is roughly:

• מה = what
• יהיה = will be
• הכי טוב = the best
• לעשות = to do

So literally:

• what will be the best to do

That sounds unnatural in English, so a more natural translation would be:

• what would be best to do
• what the best thing to do will be

This is a very common kind of Hebrew phrasing.

Because Hebrew often uses the masculine singular as a kind of default in impersonal expressions like this.

In מה יהיה הכי טוב לעשות, there is no explicit noun like plan, option, or thing. So Hebrew uses יהיה as the default form.

You can think of it as if an implied masculine noun is there, such as:

• מה יהיה הדבר הכי טוב לעשות

But that noun is not actually said.

If there were an explicit feminine noun, the agreement would change. For example:

• מה תהיה הדרך הכי טובה? = What will be the best way?

Because לעשות makes it clear that the sentence is about what action to take.

Compare:

• מה יהיה הכי טוב = what will be best
• מה יהיה הכי טוב לעשות = what will be best to do

Without לעשות, the idea is more general. With לעשות, the speaker is specifically talking about the best course of action.

Because both infinitives depend on the same verb נוכל.

So the structure is:

• נוכל לדבר... ולבדוק...
• we can talk... and check/see...

This is exactly like English:

• We can talk about it and see what to do

Hebrew often uses one conjugated verb followed by multiple infinitives linked with ו־ (and). Repeating נוכל would be possible for emphasis, but it is normally unnecessary.

Yes, that would also be possible, but the nuance is a little different.

• מה הכי טוב לעשות = what is best to do
• מה יהיה הכי טוב לעשות = what will be best to do

Using יהיה makes the sentence feel more forward-looking. It suggests that after talking about today’s events, you will decide what the best action will be.

So in this context, יהיה fits well because the discussion and decision are still in the future.