De or het theekransje?

The correct Dutch article is:

het theekransje

Rule Diminutives (-je, -tje, -pje): always het. See the rule

How to use theekransje

the theekransjehet theekransje
this theekransjedit theekransje
that theekransjedat theekransje
our theekransjeons theekransje
your theekransjejouw theekransje
every theekransjeelk theekransje
which theekransje?welk theekransje?
a big theekransje / the big theekransjeeen groot theekransje, het grote theekransje