לא נתחיל את שריפת הביסק, אלא אם כן הייבוש יסתיים.

In Hebrew, the verb itself usually tells you the person and number.

• נתחיל = we will begin / we will start
• the prefix נ־ in the future tense marks first person plural: we

So Hebrew does not need a separate word for we here.
The subject is built into the verb.

Related forms:

• אתחיל = I will begin
• תתחיל = you will begin / she will begin
• יתחיל = he will begin
• נתחיל = we will begin

The base verb is להתחיל.

לא is the normal word for negating ordinary verbs in Hebrew.

So:

• נתחיל = we will begin
• לא נתחיל = we will not begin

This is the standard way to negate past, present, and future verb forms in normal statements.

That is different from:

• אל, which is mainly used for negative commands
• אין, which is used in different kinds of present-tense existential/nominal sentences

So here לא is exactly what you want.

את marks a definite direct object.

Here, the thing being started is שריפת הביסק, so that phrase is the direct object of נתחיל.

Why is it definite? Because שריפת הביסק is a construct phrase, and in Hebrew a construct phrase becomes definite if the second noun is definite.

• הביסק = the bisque
• therefore שריפת הביסק = the bisque firing / the firing of the bisque, as a definite thing

Because the object is definite, Hebrew uses את:

• לא נתחיל את שריפת הביסק

If the object were not definite, there would usually be no את.

It is a construct chain (called סמיכות in Hebrew).

The phrase is built like this:

• שריפה = firing / burning
• שריפת = the construct form of שריפה
• הביסק = the bisque

So שריפת הביסק literally means something like:

• the firing of the bisque

In smoother English, especially in a ceramics context, that becomes:

• the bisque firing

A few important things about this structure:

1. The first noun changes form:

   • שריפה → שריפת

2. The ה־ for definiteness usually appears on the second noun, not the first:

   • not השריפת הביסק
   • but שריפת הביסק

3. The whole phrase gets its definiteness from the second noun.

This type of noun chain is very common in Hebrew, especially in formal, technical, or compact phrasing.

Yes. אלא אם כן is a fixed expression meaning unless.

So:

• לא נתחיל את שריפת הביסק, אלא אם כן...
• We will not begin the bisque firing, unless...

Literally, the parts are roughly:

• אלא = except / but rather
• אם = if
• כן = so / indeed

But as a whole, you should learn אלא אם כן as one unit meaning unless.

It is fairly common, especially in:

• instructions
• technical writing
• formal speech
• warnings and procedures

It sounds a bit more formal and set than some other ways of expressing a condition.

This is a very common difference between English and Hebrew.

In Hebrew, when the situation is in the future, the subordinate clause often also uses the future tense:

• אלא אם כן הייבוש יסתיים

Even if English might say:

• unless the drying is finished
• unless the drying ends
• unless the drying has been completed

Hebrew naturally uses the future form יסתיים.

So this is normal Hebrew grammar, not an error or over-literal translation.

This is an important distinction.

• יסתיים comes from להסתיים = to be completed / to come to an end
• יסיים comes from לסיים = to finish something

So:

• הייבוש יסתיים = the drying will be completed / will come to an end
• מישהו יסיים את הייבוש = someone will finish the drying

In other words:

• להסתיים is used when the process itself reaches completion
• לסיים is used when an agent finishes something

Here, the drying is the process that reaches its endpoint, so יסתיים is the correct choice.

Because it refers to a specific drying process or drying stage, not drying in general.

• ייבוש = drying
• הייבוש = the drying

In context, this probably means the known drying stage of the specific pieces being worked on. So the definite article ה־ makes sense.

Also notice that הייבוש is the subject of יסתיים, and the verb agrees with it as a singular masculine noun:

• הייבוש יסתיים

Hebrew usually does not need a separate subject pronoun when the noun itself is present.

Here the subject is explicitly stated:

• הייבוש = the drying

So Hebrew simply says:

• הייבוש יסתיים = the drying will be completed

You would not normally add a separate pronoun like הוא unless you wanted extra emphasis or contrast.

Yes, a closely related alternative would be:

• לא נתחיל את שריפת הביסק עד שהייבוש יסתיים

That means:

• We will not begin the bisque firing until the drying is completed

In many real-life contexts, that is very close in meaning.

The nuance is:

• אלא אם כן presents it as a condition: unless
• עד ש־ presents it as a time boundary: until

So the original sentence sounds a bit more conditional/formal, while עד ש־ may sound a bit more straightforward and time-based.

Not completely. Hebrew word order is flexible.

The sentence uses:

• הייבוש יסתיים

This is a natural subject + verb order.

But you may also encounter:

• יסתיים הייבוש

That is also grammatical, and it can sound a bit more formal, literary, or stylistically different depending on context.

So the version in your sentence is perfectly normal, but it is not the only possible order.