年月, としつき, ねんげつ
months and years
あれだけのコインを収集するのにどれだけの年月がかかりましたか。
が
Particle
1. indicates the subject of a sentence
literary in modern Japanese; usu. written as ヶ in place names
2. indicates possession
Conjunction
3. but, however, (and) yet, though, although, while
4. and
5. used after an introductory remark or explanation