Please forgive my writing mistakes

I am writing a pen pal in Japan. I know I make errors and I just realized I made a silly mistake in my last letter. I would like to send a disclaimer when I next write to him. You know, like in English we might lightly write, ''Please forgive any grammatical or spelling errors.'' Or ''sorry for all the Japanese language mistakes,'' or some such. Would love to add a short disclaimer like that next time around, since there are sure to be more of those in my letters.

Please only write the answer in hiragana if you don't mind. Thanks!

Hi, 3olives.
Why only in hiragana... to study??

Friendly:
にほんごがへんだったら、わらってゆるして！
にほんごにまちがいがあったら、ごめんなさい。
もし、にほんごにおかしなところがあっても、ゆるしてください。

A bit formal:
ふてきせつなことばづかいがありましたら、もうしわけございませんが、いたらぬてんは、ごようしゃください。

BTW, I often said "Excuse my poor English".
But I'm not sure if this is correct.
(Because I have no friends who speak English.)
It's funny English, I wonder??

No. "Excuse my poor English" is perfectly correct :)

@Stan Norrell Thanky you!(^-^)/

Thank you very much for your answer! I need the answer in hiragana because I don't know many kanji yet.

Japanese will take me forever to learn I think.

Reading Japanese newspaper for kids can help you to build a good vocabulary and kanji for more details please visit;

http://allaboutjap.blogspot.in/2012/12/read-japanese-newspaper-for-kid...