tegami o okuru mae ni, atesaki o mou ichido kakuninshimasu.

Before sending the letter, I check the address one more time.

Breakdown of tegami o okuru mae ni, atesaki o mou ichido kakuninshimasu.

• を: direct object particle
• に: time particle
• 手紙てがみ: letter
• 前まえ: before

Questions & Answers about tegami o okuru mae ni, atesaki o mou ichido kakuninshimasu.

How do you read this sentence?

It is read:

てがみ を おくる まえ に、あてさき を もう いちど かくにんします。

Word by word:

• 手紙 = てがみ = letter
• 送る = おくる = to send
• 前に = まえに = before
• 宛先 = あてさき = address / destination / addressee
• もう一度 = もういちど = one more time / again
• 確認します = かくにんします = confirm / check

Why is 送る in the dictionary form before 前に?

Because the pattern is:

• Verb dictionary form + 前に = before doing ...

So:

• 送る前に = before sending

This is a very common grammar pattern.

Examples:

• 食べる前に、手を洗います。 = Before eating, I wash my hands.
• 寝る前に、本を読みます。 = Before sleeping, I read a book.

So in your sentence, 手紙を送る前に means before sending the letter.

Why is it 前に and not just 前?