If someone finishes p’sukei d’zimra ahead of the chazan and has already said Yishtabach, what is permitted for this individual to daven/say before the chazan begins kaddish?
Can one say karbonos? Parts of p’sukei d’zimra that may have been skipped? Tehillim?
You are allowed to learn with your mind and eyes, but you can’t say the words, even if it just reading tehillim. However parts of davening, such as parts of pesukei d’zimra and korbanos that you skipped may be said then. It is also permitted to say asher yotzar, and one may put on tallis and teffilin and say the bracha on them, (but not the pesukim that are said after them). (A chazan should put on tallis and teffllin before yishtabach so he won’t be mafsik between yishtabach and kaddish)
Shulchan Aruch O:CH 54-3, Aruch Hashulchan 53-4, Be’er Moshe 3-20, Shevet Hakehosi 6-65, Piskei Teshuvos 54-3. M:B 54-13, Ishei Yisroel chap. 16-ftnt. 100 in the name of R’ Chaim Kanievsky shlit”a, Poskim.