Как правильно написать прописью ' i '; ' I '; (ай)

Вот так пишу я. Фото из Вики.

once my mother and i were invited to a local theater. tickets were booked in advance. i knew that our seats would be in box. to be honest, my mother was not quite satisfied. she said she did not know the play and had a fear that this play is for adults, not for children of my age. certainly, i looked forward to the day of performance

he is blue and he has four arms and two legs.he isn't a very big alien.he is fat.he has green hair.