הם התחילו לאכול בלי שחיכו לי, כי הגעתי מאוחר מאוד.

Literally, it is something like without that they waited for me.

In natural English, that becomes without waiting for me or without having waited for me.

Here is the breakdown:

• בלי = without
• ש־ = that / a connector introducing a clause
• חיכו = they waited
• לי = for me

So Hebrew uses a full clause here: without that they waited for me, where English usually prefers without waiting for me.

The ש־ introduces a subordinate clause.

In this sentence, בלי ש... means without ...ing or without the fact that.... It is a very common Hebrew structure.

Compare:

• בלי שחיכו לי = without waiting for me
• בלי שראיתי = without seeing
• בלי שהוא אמר לי = without him telling me

So ש־ is needed because what follows is a finite verb: חיכו.

Yes, בלי לחכות לי is also possible, but it is not exactly the same in tone.

• בלי לחכות לי = without waiting for me
• בלי שחיכו לי = without them waiting for me

The version with ש + past verb sounds a bit more explicit, because it clearly refers to their actual action in the situation.

So:

• הם התחילו לאכול בלי לחכות לי = perfectly natural
• הם התחילו לאכול בלי שחיכו לי = also natural, slightly fuller/more clause-like

Both are good Hebrew.

Because the verb לחכות takes the preposition ל־ when it means to wait for someone.

So Hebrew says:

• חיכיתי לך = I waited for you
• חיכו לי = they waited for me
• אנחנו מחכים להם = we are waiting for them

For an English speaker, this is important because English uses a direct object (waited for me), but Hebrew uses ל־.

So חיכו אותי is incorrect in standard Hebrew.

In Hebrew, the verb must still show person, number, and often gender, even if the subject pronoun is already present.

So:

• הם התחילו = they started
• חיכו = they waited

Hebrew does not use a neutral verb form after a subject pronoun the way English does. The plural marking is part of normal Hebrew grammar.

Also, Hebrew often omits subject pronouns entirely when the verb already makes the subject clear. For example, you could say:

• התחילו לאכול בלי שחיכו לי = They started eating without waiting for me

The הם is optional here.

Both are in the past tense.

• התחילו = they started
• הגעתי = I arrived

Breakdown:

• התחילו comes from the verb להתחיל = to start / to begin
• הגעתי comes from להגיע = to arrive

The ending ־תי in הגעתי is the normal I ending in the past tense.

Examples:

• כתבתי = I wrote
• אמרתי = I said
• הגעתי = I arrived

After התחיל (started / began), Hebrew normally uses the infinitive of the next verb.

So:

• התחילו לאכול = they started to eat
• התחלתי ללמוד = I started to study
• היא התחילה לדבר = she started to speak

Here:

• לאכול is the infinitive to eat

This is very similar to English started to eat.

Because the sentence is talking about a completed event: I arrived very late.

• הגעתי = I arrived
• הייתי מאחר = I was late / I used to be late / I would be late, depending on context

Here the point is that the speaker actually arrived late on that occasion, so הגעתי is the natural choice.

If you said כי איחרתי מאוד, that would also work and means because I was very late / because I arrived very late.

So both of these are natural:

• כי הגעתי מאוחר מאוד
• כי איחרתי מאוד

Both can occur, but מאוחר מאוד is the more natural and common order here.

• מאוחר = late
• מאוד = very

In Hebrew, מאוד often comes after the adjective:

• טוב מאוד = very good
• יפה מאוד = very beautiful / very nice
• מאוחר מאוד = very late

So for learners, the safest pattern is:

adjective + מאוד

The comma separates the main clause from the reason clause.

Main clause:

• הם התחילו לאכול בלי שחיכו לי
  They started eating without waiting for me

Reason clause:

• כי הגעתי מאוחר מאוד
  because I arrived very late

In modern Hebrew punctuation, a comma before כי is common when the sentence is long enough or when the writer wants a clear pause. In shorter sentences, punctuation can vary a bit by style.

So the comma here is natural and helpful, but punctuation in Hebrew is sometimes a little more flexible than learners expect.

No, it is not strictly necessary.

You can say:

• הם התחילו לאכול בלי שחיכו לי, כי הגעתי מאוחר מאוד.
• התחילו לאכול בלי שחיכו לי, כי הגעתי מאוחר מאוד.

Both are grammatical.

Why? Because התחילו already tells you the subject is they.

Still, adding הם can be useful for:

• emphasis
• clarity
• contrast with someone else

So הם is optional, but perfectly normal.

Yes:

• הם = they
• התחילו = started
• לאכול = to eat / eating
• בלי = without
• שחיכו = that they waited
• לי = for me
• כי = because
• הגעתי = I arrived
• מאוחר מאוד = very late

So the structure is:

They started to eat + without waiting for me + because I arrived very late.

A very natural English translation is:

They started eating without waiting for me, because I arrived very late.