〔未経験な〕be inexperienced ((in))；〔慣れていない〕be unaccustomed ((to))，be new ((to, at))
- His failure was due to his inexperience [lack of experience].
- He is inexperienced in this job.／He is unaccustomed [new] to this job.
- He is a stranger in this town.／He is unfamiliar with this town.
- I ordered a meal in awkward English.