ずつ => a piece; each; at a time N5
More or less in quantity
~且つ(かつ) => and N1
Line up, list
つつ => while; even though; despite ~ N2
つつ/つつも => While A, B. Although A (is beng done), B N2
Information, Report
につけ~につけ => each time, whenever, either way N2
べつに => separately N2
Description
つ~つ => Doing A and B (repeatedly, one after another) N1
Information, Report
からつくる/でつくる => made from; made with N4
ひとつ => A little N3
Repetition, habit
いつかの ... => Previously N4
Time
つつある => to be doing; to be in the process of doing ~ N2
いつも => always; usually; habitually N5