Ich entschuldige mich per E‑Mail, weil ich gestern zu spät gekommen bin.

I apologize by email because I arrived too late yesterday.

Breakdown of Ich entschuldige mich per E‑Mail, weil ich gestern zu spät gekommen bin.

• sein: to be
• ich: I
• weil: because
• spät: late
• Gestern: yesterday
• mich: myself
• zu: too
• per: by
• die E‑Mail: the e-mail
• sich entschuldigen: to apologize
• kommen: to arrive

Questions & Answers about Ich entschuldige mich per E‑Mail, weil ich gestern zu spät gekommen bin.

Why does entschuldigen need mich here?

Because sich entschuldigen is used as a reflexive verb in German: (sich) entschuldigen = to apologize.
So you say Ich entschuldige mich (literally: I apologize myself, idiomatically: I apologize).
The reflexive pronoun is accusative here: mich / dich / sich / uns / euch / sich.

Is Ich entschuldige mich always the best way to say “I apologize”?

It’s common and correct, but depending on context it can sound a bit like excusing yourself (stepping away). Alternatives you’ll often hear:

• Entschuldigung! (quick, informal/apologizing)
• Es tut mir leid. (very common, “I’m sorry”)
• Ich möchte mich entschuldigen. (more formal/polite)
• Bitte entschuldigen Sie … (formal, often with a noun: die Verspätung)

Why is it per E‑Mail and not mit/via E‑Mail?

per is a standard preposition in German meaning by/through, often used for communication methods: per E‑Mail, per Post, per Telefon.
via E‑Mail is also possible (slightly more “international/technical” style).
mit E‑Mail is usually not used for “by email” in this sense.

Does per require a specific case?

In practice, per is most often used without an article, so you don’t see case marking: per E‑Mail.
If an article is used, many speakers treat it like accusative (common in usage), but it varies and is style-dependent. Most learners can safely stick to the fixed adverbial: per + noun (no article).

Why is there a comma before weil?

Because weil introduces a subordinate clause (Nebensatz). In German, subordinate clauses are separated from the main clause with a comma:

• Ich entschuldige mich per E‑Mail, weil …

Why does the verb go to the end in the weil clause?

In a weil clause, German uses verb-final word order. With the perfect tense, that means the participle comes before the auxiliary, and the auxiliary is last:

• … weil ich gestern zu spät gekommen bin.

Why is it gekommen bin (with sein) and not gekommen habe?

Many movement/change-of-state verbs form the perfect tense with sein, and kommen is one of them:

• ich bin gekommen, not ich habe gekommen

Why is it gestern … gekommen bin (perfect tense) instead of a simple past form?

In spoken and everyday German, the perfect tense is very common for past events:

• … weil ich gestern zu spät gekommen bin. (common) The simple past is also possible, especially in writing or in some regions:
• … weil ich gestern zu spät kam.

What does zu spät mean grammatically, and where does it go?

zu spät is an adverbial expression meaning too late. It commonly sits in the “middle field” before the participle:

• … gestern zu spät gekommen bin.
  You could also move time expressions around for emphasis, but this version is very natural.

Why is gestern placed where it is?

German often follows a loose tendency like time–manner–place in the middle of the clause. Here:

• gestern (time)
• zu spät (manner/degree) So … weil ich gestern zu spät gekommen bin sounds very normal.

Could I say dafür, dass ich … instead of weil ich …?

Yes, and it changes the framing slightly:

• … weil ich zu spät gekommen bin = giving the reason
• … dafür, dass ich zu spät gekommen bin = apologizing for the fact that it happened
  A common variant is:
• Ich entschuldige mich per E‑Mail dafür, dass ich gestern zu spät gekommen bin.

Who am I apologizing to? Shouldn’t there be bei dir/bei Ihnen?

The sentence is grammatically complete without stating the addressee, but you can add it if needed:

• Ich entschuldige mich bei dir … (informal)
• Ich entschuldige mich bei Ihnen … (formal) You can also apologize for something explicitly:
• Ich entschuldige mich für die Verspätung.