N5 — outside your level filter
Is said whole, with nothing composed onto it and takes no copula, so there is no paradigm to conjugate.
一人で
hitoridealone, by oneselfN5expression
Readings and definitions from JMdict, © the Electronic Dictionary Research and Development Group (EDRDG), used under CC BY-SA 4.0; the words themselves come from the Tanos JLPT lists.