All of these are correct except "malala", but you're just using different conjugations of the roots "alala" and "tanda". The correct use of each of these heavily depends on the context in which they're intended. For instance, you could tell someone to remember something by using what's called the imperative (also called "command") form of either, which would be "Alahanin mo..." or "Tandaan mo..." Let's look at a conjugation chart: The ma- prefix is used here to indicate the ability of the actor to perform the verb, in this case to remember. Infinitive/imperative abilitative: N/A for abilitative verbs, since you can't really command someone to have the ability to do something Past abilitative: naalala Present abilitative: naaalala Future abilitative: maaalala However, the -in- affix can be used to command and refers to actions done intentionally without necessarily referring to ability. As you'll notice, this usage is irregular because it's used as a prefix rather than as an infix that you might've seen in other verbs like "pinalakad" or "binasa": Infinitive/imperative: alahanin Past: inalala Present: inaalala Future: alalahanin As for "tanda", it's often translated to mean "to remember" but it also means "to note" and is in fact the noun for "note, sign or mark". The conjugation used when it's translated as "remember" is either a combination of the ma- abilitative prefix and the -an demonstrative (shows locations and receivers, among other things), or the -in- infix with -an. Ma- -an: Infinitive/imperative: N/A Past: natandaan Present: natatandaan Future: matatandaan -in- -an: Infinitive/imperative: tandaan Past: tinandaan Present: tinatandaan Future: tatandaan Hope that answers your question!

It depends on how you want to say it. For imperative, it's either "tandaan" or "alalahanin" like "Tandaan / Alalahanin mo 'yan. = Remember that." For interrogative, Naaalala mo (ba)? or Natatandaan mo (ba)? = Do you remember?; Maalaala=Would remember For declarative, similar forms apply like with the interrogative, example: Naaalala ko noong... = I remember when... *Malala comes from the rootverb "lala" meaning "worse". Good luck! ;)