Question: am I correct to suggest that natulog or nagtulog is th

Natulog is the completed aspect of sleep.Kumusta ang tulog mo is fine. There isn't really a verb in that sentence.Kumusta ang tulog mo
(how is/was) (focus marker) (sleep, noun) (of you, genetive 2nd p singular pronoun)Even in English we say "how was your sleep". Sleep here is also a noun.

@akosikoneho Aha, makes sense. Maraming salamat po.

From my very limited knowledge, one of the joys of Tagalog is that you can put mag in front of virtually anything to make it a verb and ang in front of pretty much any verb root to make it a noun. Gross generalisation I know.
Sleep is rarely used as a noun in English though, I think. Normally we would ask How did you sleep? or Did you sleep well? Both verbs. Sleep as a noun is usually 'deep' English. My sleep was interrupted by... or Lack of sleep is responsible for...

@JohnD That's a good shortcut where at least you'll be understandable...of course, it will often be bad grammar...but not always! ; )

@TLDCAdmin I remember my wife once being asked what our son ate for breakfast. 'Magcereal siya' was her reply

@Fujishooter - Natulog is the past tense of sleep. Nagtulog is used in the following; “Nagtulog lang ako maghapon.” (I just slept all day) The proper response for your question, like in English, should be,”Okay naman,” or “Nakatulog ako ng mahimbing (I slept well).” Notice the prefix /naka-/ in “nakatulog.” It is always joined with a verb or adjective to state a condition. The response to her question can be what I said earlier or the following: “Hindi ako nakatulog ng mabuti (I didn’t sleep well)” or, “Mabuti naman (It was good).”

@Minette747 Maraming Salamat

@Fujishooter Walang anuman. Nawa’y nakatulong. (Hopefully it helps.)

@JohnD Possibly "nag-cereal".

@akosikoneho I think the question was posed as to what he ate on a regular basis rather than what he ate that morning. So I think that mag would be correct. But I appreciate that it would be be nag for the past tense if the question referred to a specific instance in the past.

@JohnD
"I remember my wife once being asked what our son ate for breakfast. 'Magcereal siya' was her reply"" I think the question was posed as to what he ate on a regular basis rather than what he ate that morning. So I think that mag would be correct. But I appreciate that it would be be nag for the past tense if the question referred to a specific instance in the past."In that case it would be nag-se-cereal siya. Nag-ro-root is used for habitual actions usually.

Habitual actions usually take the present tense (actually aspect, not tense) as stated by AkoSiKoneho who one of our resident experts. But for examples sake, and my own learning, I will expand on this with what I believe are the possible formations:magcereal = to eat cereal
magceceral = will eat cereal (in the future)
nagceceral = eating cereal (currently) OR habitually eats cereal
nagcereal = ate cereal (in the past)nagcecereal siya = He/she is eating cereal (right now) or He/she eats cereal (regularly) See here:
learningtagalog.com/ grammar/verbs/aspect s/overview.htmlIt's a very interesting language indeed.

@akosikoneho Thank you. I (mistakenly) thought that you would use the infinitive in this case. Always something new to learn