N4 — outside your level filter
write + (and…) + sorry for doing — an apology with the act named in front of it
kaite sumimasen
sorry for doing (something) — an apology with the act named in front of it
meaning: sorry for writing
返事が遅れてすみません。今、確認しました。
henji ga okurete sumimasen. ima, kakunin shimashita.
I'm sorry for being late with my reply — I've just seen it. neutral
昨日は連絡できなくてごめん。バタバタしてた。
kinou wa renraku dekinakute gomen. batabata shiteta.
Sorry I couldn't get in touch yesterday — things were hectic. casual