There isn't a verb that translates specifically as "to be" as in "To be, or not to be..." but the verb "maging" is translated as "to become" and often acts as an existential verb. For instance, you'd say "Doctor ako" which word-for-word means "Doctor I", meaning the existential phrase "I am a doctor" is implied. To use "maging", however, you'd usually say it in the past or future tense: Naging doctor ako. = I become a doctor. Magiging doctor ako. = I will become a doctor. "Nagiging", the present tense form, can mean "becoming" to indicate something that happens constantly as opposed to only in the past or future, or it can mean something that is happening right now: Nagiging mas malinaw ang aking kaisipan. = My mind is becoming more clear. Siya ay nagiging mas malungkot. = She is becoming more sad. Some grammar references translate "ay" is mean "is", but this is incorrect.

"to be" is maging in tagalog