21. The alveolar liquids / l / and / r / are in free variation as in many African languages. 22. A small fraction of variation in interlanguage is " free variation ", when the learner uses two forms interchangeably. 23. Older speakers tend to use a trilled in free variation with, while younger speakers tend to use a uvular. 24. The realization of the phoneme is in free variation between a voiced retroflex lateral and a voiced retroflex stop. 25. In certain languages, such as Norwegian the voiced labiodental fricative is in a free variation with the labiodental approximant. 26. Before, there is free variation between this and so that " nanac " ('exceedingly') may be realized as or. 27. And are reported to be in free variation , although reports of could be a misinterpretation of unaspirated by English speakers. 28. Otherwise, the phones and are in free variation with each other so that ('my brother') may be realized as either or. 29. The unusual three stanzas, all beginning with the words " ", are delivered as free variations and closed by a coda. 30. Free variation in the use of a language feature is usually taken as a sign that it has not been fully acquired.