Atel/o
Atel/o- incomplete; imperfect
The imperfect "tú" form of the verb "ser" is "eras" and the imperfect "usted" form is "era".
Tuvo
The combining form for dermatologist is dermat/o.
The combining form for "gingivo-" is "gingiv/o-".
The combining form for potassium is kal/i.
-ologist is the combining form meaning specialist.
The imperfect progressive tense has two components: the imperfect form of haber and the present participle. Haber is regular in the imperfect tense: había, habías, había, habíamos, habíais, habían The present participle depends on the verb and there are several irregular present participle types (pidiendo for pedir, durmiendo for dormir, etc.) However, because the present participle is the same as the one used in the present progressive, if you know the irregulars from that then there is no need to relearn them here.
The combining form for sugar is "glyc/o".
The combining form for "flesh" is "sarc/o" or "sarc-".
The combining form is that the prefix osteo- is added.
The combining form for cervix is cervic/o.