ba - used to mean is or are in a question
Matagal ka na ba dito?

Have you been here for long?
Tapos ka na ba? Are you finished?

nga - really
Alin nga ba ang ginawa ko?

 Which one did I really make?
Ikaw nga ba iyan? Is that really you?

nga - then
Ikaw na nga ang magsabi sa kanya.

Then, you be the one to tell her.
Ayoko na ngang tumulong.

 I don't want to help then.

naman - again
Ikaw na naman. It is you again.

naman - this time
Ikaw naman ang magbantay.

You guard the place this time.
Pakiusod naman ang mesa.

Can you this time please move the table?

lang - only
Minsan lang kitang makausap.

 Only once can I talk with you.
Sampu lang ang inorder ko nito.

 I ordered only ten of these.