gaghl641295-san, マイケルsan,
kon'nichiwa!
Thank you very much for the kind help, マイケルsan!
Yes; マイケルsan is very right. There're no simple explanation for "how to make complex sentences"
even because I don't know what exactly you want to know and/or why you're facing problems.
You can join some forums where people are trying to compose sentences in Japanese, and/or
leave comments after the lesson with practice! You can practice Japanese sentences there,
and we're always happy to help you! Of course, you can ask us any questions too.
Good luck!
Natsuko(奈津子),
Team JapanesePod101.com