Learn Italian: Purtroppo, ieri sera sono dovuto restare in ufficio. - Unfortunately, last night I had to stay in the office.

This is the special rule for modal verbs like dovere (to have to). In the passato prossimo (the recent past tense), modal verbs borrow the auxiliary verb of the action verb that follows them. Since restare (to stay) is a verb that always takes essere (to be), dovere must also use essere here. That is why we say sono dovuto instead of ho dovuto.

Would a female speaker say this sentence exactly the same way?

No, she would say sono dovuta restare. Whenever you use essere as the helping verb, the past participle (in this case, dovuto) must change its ending to match the gender and number of the person who is the subject. A female speaker changes the masculine -o to a feminine -a.

Why is it 'in ufficio' without the word for 'the' (nell'ufficio)?

For many everyday locations, Italian uses just in without a definite article. You will see this with in ufficio (in/to the office), in banca (to the bank), and in farmacia (to the pharmacy). You only use nell'ufficio if you are specifying exactly which office, like nell'ufficio di Marco (in Marco's office).

Can I say 'ieri notte' instead of 'ieri sera' for 'last night'?