私は or この手紙は that means I wrote this letter


‎What is the difference between

> 私はあなたの鉛筆でこの手紙を書きました。

and

> この手紙はあなたの鉛筆で書きました。

Do the two sentences have the same meaning? I'm trying to say:

> I wrote this letter with your pen.




It's basically the same meaning. They both mean "I wrote this letter with your
pencil" (not pen).

> 私はあなたの鉛筆でこの手紙を書きました。

This one has "I" at the beginning.

> この手紙はあなたの鉛筆で書きました。

This one doesn't have "I". That's ok. You can often leave out 私は in Japanese
because it's clear from context. The other difference is, 手紙 became the topic
of the sentence, so its particle を changed to は.

