Prepositions between verbs
Sometimes you use a word in between two verbs when the first is conjugated and the second is infinitive. How do you know which verbs to do this for, and is a preposition other than a ever used? Thanks! Ejemplos:
- Voy a terminar la tarea.
- Me gusta cocinar. (no connector)
- Empezar a hacer la tarea.
- Tratamos/intentamos a ir a la fiesta.
5 Answers
This will get you started on learning how prepositions are used after some verbs followed by either another verb infinitive or an object.
Hello Beng and welcome to the SpanishDict forum 
Sometimes you use a word in between two verbs when the first is conjugated and the second is infinitive. How do you know which verbs to do this for?
This comes with observation and practice. You observe other native and advanced speakers who write Spanish such as Heidi, Gekkosan, Raul and Nelson (natives) and Marianne, Jen, Gintar (advanced) and others, and take note of how they write good Spanish and learn from them and apply what you have just learnt and it will sink in after a great deal of practice! 
and is a preposition other than a ever used? Thanks!
Yes, prepositions such as de (meaning ''of'') and en (meaning ''in'' ''at'' '' on'' or ''into'') are frequently used. and of course por and para.
Voy a tratar de explicar = I am going to try to explain
¿Prefieres viajar en coche o en tren?
= Do you prefer to travel by car or by train?
No entremos en la casa
= Let's not go into the house
Lo hace para ganar dinero
= He does it (in order) to earn money
I hope this helps :-)
Last three examples courtesy of Collins''Easy learning Complete Spanish''
Corrijan mi español, por favor
The rules are very similar to the rules for prepositions in English: there aren't any and you have to memorize the meanings of various combinations of conjugated verb + preposition.
If you think about the situation in English for a few minutes, you will notice that many verbs can be used with several different prepositions, each one resulting in a combination with a different meaning, but the way in which the meanings change for different verbs in combination with a given preposition is random.
run in
run on
run up
run for
stand in
stand on
stand up
stand for
call in
call on
call up
call for
etc.´
In addition to what Qfreed posted:
You memorize them.
