Verbs
The verbs are probably the most complicated and difficult aspect of Tagalog to explain to non-Tagalog speakers. They work very differently from English ones, obviously. There are only three tenses which are past, present and future. The tenses of Tagalog verbs are only concerned with whether something happened, happens or will happen.
Since Tagalog uses agglutination, the verb is made up of the verb root and an appropriate affix. An affix can be added to the beginning (prefix), the middle (infix) or at the end (suffix) in order to change the meaning of the word and use in a sentence.
Look at this verb "kumain" which is the infinitive meaning 'to eat'. Its verb root is "kain".
The infix "-um-" is added to the root "kain" to turn it into the infinitive. This is done by adding the infix after the first consonantal letter.
Tagalog uses reduplication which is the process of repeating the syllable in order to convey its tense.
So to turn "kain" into the present tense, repeat the first syllable to get "kakain", then add the infix "-um-" after the first consonantal letter and you get "kumakain" which is the present meaning 'eat/eats'. Note that the present can also be continuous present.