Verbs (Present 2) did me in today
I apologize if this is way too general (I've got one foot out of the office) but HOW can I tell when a verb needs to have a preposition after it (like på) and when it doesn't? For example, "Trust him" --> it's not "litar honom" but "litar på honom." Any help?
When you get to Present 3 there is an explanation of different types of verbs. I believe what you are describing is a particle verb, and it looks like you just have to remember them. Without the particle (på in this case) the verb would mean something completely different. Basically, if you are mapping words directly, don't remember "litar" as trust, but rather "litar på" as trust. The example they give is the difference between "turn the radio" and "turn off the radio" in English.
Almost, but not quite right. The particle verbs are verbs followed by particles that are always stressed, but på in lita på is not stressed so it is just an obligatory preposition. This works the same way as in English: some verbs need certain prepositions, others don't, and you just need to learn which one works how. So an example to compare with in English in this case is verbs like wait for. You don't just say I wait him, you need the preposition for. Or you can't say I agree you without the preposition with.
I totally agree with you that you should always memorize those verbs as units.