counter
counter for Sino-Japanese words
Attaches directly to a number and precedes the noun being counted. Common with months (か月), places (か所), countries (か国), etc. Often written as ヶ or ケ in compounds.
３か月前に引っ越しました。
I moved three months ago.
このビルには５か所の出入り口がある。
This building has five entrances/exits.
Rarely used kanji form for this counter; usually read こ.
Archaic variant, almost never used.
Derived from the kanji 箇 (ka), a counter for items. The small ke form ヶ is a simplification of 箇, and か is the phonetic reading.