Non-occurrence in isolation is given as the primary criterion for boundness in most linguistics textbooks.
[5] English language affixes are almost exclusively prefixes or suffixes: pre- in "precaution" and -ment in "shipment".
A similar example is given in Chinese; most of its morphemes are monosyllabic and identified with a Chinese character because of the largely morphosyllabic script, but disyllabic words exist that cannot be analyzed into independent morphemes, such as 蝴蝶 húdié 'butterfly'.
Linguists usually distinguish between productive and unproductive forms when speaking about morphemes.
But as ten- is not used in English to form new words, most linguists would not consider it to be a morpheme at all.