root word: tagal
taking a long time

Matagal na kitang hinihintay.
I've been waiting for you for a long time.

Matagal ka na ba sa Pilipinas?
Have you been in the Philippines for a long time?

Matagal na tayong hindi nagkita.
You and I haven't seen each other in a long while.

Matagal bago mangyari iyan.
It'll be a long time before that happens.

will be taking awhile

Matatagalan ako.
It might take me awhile.
The Tagalog word for 'slow' is mabagal.