just   ~~~>        zeitlich  &  mengenmäßig

1. recently  ---> I just washed the floor, it's wet.  (zeitlich  =  gerade eben) )

2. only        ---> I just got one sister. (mengenmäßig  =   nur 1 Schwester))

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only    ~~~>     "mengenmäßig"

1. Only two students came to ... ---> Nur 2 Studenten ... ( mengenmäßig) 

Only can be replaced by just in most situations :

Only” and “just” are interchangeable with definition 2 of “just,” but not with definition 1.

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In the expression

 “If only…”    you can use    “just”    if you change the structure a little bit:

If only I had studied harder...  =       If I had just studied harder ...   - espressoenglisch