mitunter
sometimes
An adverb meaning: sometimes, occasionally, from time to time.
Obwohl er sonst sehr ruhig ist, kann er mitunter auch sehr gesprächig sein.
Although he is usually very quiet, he can sometimes be very talkative.

sometimes
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sometimes
An adverb meaning: sometimes, occasionally, from time to time.
Obwohl er sonst sehr ruhig ist, kann er mitunter auch sehr gesprächig sein.
Although he is usually very quiet, he can sometimes be very talkative.

The word is made up of 'mit' (with) and 'unter' (under/among). Although the individual parts are recognizable, the meaning 'sometimes' cannot be directly derived and must be learned as a fixed unit.
Die Arbeit im Garten kann mitunter sehr anstrengend sein.
Working in the garden can sometimes be very exhausting.
'Mitunter' can stand in position 1; then the verb follows directly after it. But it can also stand inside the sentence after the verb and the subject.
Mitunter vergesse ich, die Blumen zu gießen.
Sometimes I forget to water the flowers.
This adverb belongs more to written language or an elevated style. It is used less often in everyday spoken language.
Die Verhandlungen gestalteten sich mitunter schwierig.
The negotiations proved difficult at times.
often
'oft' and 'mitunter' differ in how frequently something happens. You use 'oft' when something happens many times or regularly. 'mitunter' means 'sometimes' or 'occasionally' and describes a clearly lower frequency. So the practical contrast is: 'oft' suggests many repetitions, while 'mitunter' suggests individual cases. 'mitunter' also sounds a bit more elevated than 'manchmal'.

Im Kurs fragt Simon mitunter nach, wenn er eine Regel nicht versteht.
In the course, Simon sometimes asks follow-up questions when he does not understand a rule.
Am Abend kocht der Kunde oft selbst, weil er Geld sparen möchte.
In the evening, the customer often cooks for himself because he wants to save money.