I'm attempting to make a sentence saying
ぼくは ともだち で はなしています
I am speaking with a friend
While making it I was just wondering if using で would be correct since I kind of felt like ともだち would be the means for which I do the verb はなしています. Maybe I would just use を here? Not sure, any help/ explanation here is appreciated
Using で in this case would be unnatural because it sounds like you're using your friend to talk. To indicate who you are talking to, use the particle と instead, meaning "with":
ぼくはともだちとはなしています
I am talking with my friend.
It is possible to use the particle で with the verb 話す, but it will indicate what means of communication you used, never who you were talking with. Some examples of when you do use で:
日本語{にほんご}で話す{はなす} - Speak in Japanese
電話{でんわ}で話す{はなす} - Talk over the phone
小声{こごえ}で話す{はなす} - Speak in a low voice
