סימנו את ארגזי הקרטון בשביל שנמצא את התכולה.

Because the verb already includes the subject.

סימנו is the past-tense, first-person plural form of לסמן, so it means we marked or we labeled. In Hebrew, you often do not need a separate subject pronoun like אנחנו unless you want emphasis or contrast.

So:

• סימנו = we marked
• אנחנו סימנו = we marked with extra emphasis on we

It comes from the verb לסמן, which can mean to mark, to label, to indicate, or to tag, depending on context.

In this sentence, the most natural sense is something like:

• we marked
• we labeled

The form סימנו is:

• past tense
• 1st person plural
• based on the root ס־מ־נ

את marks a definite direct object. It usually is not translated into English.

So in this sentence:

• את ארגזי הקרטון = the direct object the cardboard boxes
• את התכולה = the direct object the contents

Hebrew uses את when the object is definite, for example:

• with ה־: התכולה
• with a definite construct phrase: ארגזי הקרטון

That is why את appears twice.

Because ארגזי הקרטון is a construct chain (סמיכות).

The basic noun is ארגזים = boxes.
But in construct form, ארגזים becomes ארגזי.

So:

• ארגזים = boxes
• ארגזי קרטון = cardboard boxes / boxes of cardboard
• ארגזי הקרטון = the cardboard boxes

This is a very common Hebrew structure, where two nouns are linked together and the first one changes form.

In a construct chain, the definite article usually appears on the last noun, and the whole phrase becomes definite.

So:

• ארגזי קרטון = cardboard boxes
• ארגזי הקרטון = the cardboard boxes

Even though ה־ is attached only to קרטון, the entire phrase is understood as definite. That is also why it can take את.

Here, בשביל does not mean a physical path.

In this sentence, בשביל means for, in order to, or so that. It introduces the purpose of the action.

So:

• סימנו את ארגזי הקרטון בשביל שנמצא את התכולה = We marked the cardboard boxes so that we could find the contents

This use of בשביל is very common in spoken Hebrew.

The ש־ is the conjunction that.

In this sentence, it helps introduce a subordinate clause after בשביל, giving the idea of so that.

So:

• בשביל שנמצא = so that we find / so that we can find

This is similar to English structures like:

• in order that we find
• so that we find

In everyday Hebrew, ש־ is extremely common and often attaches directly to the next word.

Here it means we will find or we can find, depending on how naturally you translate it into English.

Without vowels, נמצא can sometimes be ambiguous in writing. In other contexts, it might mean is found. But in this sentence, the context makes the meaning clear:

• בשביל שנמצא = so that we find / can find

So here it is the future, first-person plural form of למצוא.

Hebrew can express purpose in more than one way.

Two common patterns are:

• כדי למצוא = in order to find
• כדי שנמצא / בשביל שנמצא = so that we find

The sentence you have uses the second pattern: a purpose clause with ש־ plus a future verb.

This has a few effects:

• it sounds very natural in spoken Hebrew
• it makes the subject explicit inside the clause: we find
• it is slightly more clause-like than the infinitive version

A close alternative would be:

• סימנו את ארגזי הקרטון כדי שנמצא את התכולה
• סימנו את ארגזי הקרטון כדי למצוא את התכולה

Both are possible, though the nuance and style can differ slightly.

תכולה means contents: the things inside a container, box, bag, room, and so on.

Even though English usually says contents in the plural, Hebrew often uses the singular noun תכולה for this idea.

So:

• התכולה = the contents

It is a somewhat neutral or practical word, often used for boxes, packages, storage, shipping, and inventory.

בשביל שנמצא is natural, especially in everyday spoken Hebrew.

However:

• כדי שנמצא sounds a bit more standard or formal
• בשביל שנמצא sounds more conversational

So the original sentence is fine, but a learner should know that כדי is often preferred in more formal writing.

You can think of it like this:

• בשביל... = very common in speech
• כדי... = a bit more neutral or formal

You know because the objects are marked as definite.

There are two main clues:

• את is used before both objects
• התכולה has ה־
• ארגזי הקרטון is a definite construct phrase because of הקרטון

So the sentence is not talking about boxes and contents in general. It is talking about particular boxes and the contents associated with them.