Llamar la atención, a must have expression!
Interest
It works like "me gusta", so that means the verb will be in it form or in they form, depending on what interest you (singular/plural).
In something
"A Pablo le llama la atención la historia del comunismo" - History of communism catches Pablo's attention / Pablo is interested in the history of communism.
In someone
"Mi marido me llamó la atención el primer día" - My husband caught my attention the first day / I noticed my husband the first day.
To find something odd, strange
"Me llamó mucho la atención no verte en la fiesta" - it caught my attention a lot not seeing you in the party / I thought it was odd not seeing you in the party.
To tell someone off/call someone out
In this case, it doesn't work like "me gusta", the verb agrees with the person doing it (the subject) and then there will be an indirect object (me, te, le...) for the person you're calling out:
"Voy a llamarle la atención a David porque no me gustó su actitud" - I'm going to call David out because I didn't like his attitude / I'm going to tell David off because I didn't like his attitud.
To stand out
Something or someone stands out in a particular situation:
"Ese perro negro llama la atención entre todos los blancos" - That black dog stands out amongst all of the white ones.
"Las luces llamaban la atención en la noche" - The lights stood out at night.
To call or draw attention to ...
Queremos a llamar la atención sobre la falta de flexibilidad en el horario - we want to call attention about a lack of flexibility in the schedule.
It can be one person drawing attention to oneself, on purpose or not, which is going to sound very similar to "catching people's attention" or "stand out" even:
Para de gritar, estás llamando la atención - Stop shouting, you're drawing attention to yourself / catching people's attention / standing out.
Mario intentó llamar la atención con sus chistes- Mario tried to draw attention to himself/call people's attention with his jokes.
More examples:
Case 1 (interest in something)
No me llama nada la atención el golf - Golf doesn't interest me.
A ella le llama mucho la atención esa película - That movie catches her attention a lot.
Case 2 (interest in person)
Manuela te llama la atención, ¿no? - You're interested in Manuela, right?
No me llama la atención tu amigo, lo siento - Your friend doesn't catch my attention, I'm sorry.
Case 3 (odd, strange)
¿No te llama la atención que la fiesta termine tan pronto? - Doesn't seem odd to you that the party ends so soon?
Les llamó la atención que Juana no los saludara - It caught their attention the fact that Juana didn't say hi to them.
Case 4 (To call out/tell off)
Nos llamaron la atención por hablar muy alto en el bar - They called us out for talking very loud at the bar.
Creo que deberías llamarle la atención por su comportamiento - I think you should call him/her out for her/his behaviour.
Case 5 (to stand out)
¡Wow! ¡Esos tulipanes morados llaman mucho la atención! - Wow! Those purple tulips stand out a lot!
La estrella de rock llamaba mucho la atencion entre los invitados - The rock star stood out a lot amongst the guests.
Case 6 (to draw attention to...)
Yo querría llamar la atención sobre las largas jornadas laborales - I would want to draw attention about the long shifts.
¡Qué ridículo es Pablo intentando llamar la atención siempre cuando estamos con chicas! - How ridicule is Pablo trying to always draw attention to himself when we're with girls.
Last example, using the picture I used for the blogpost (above) let's see if you know which of the 6 cases is!
El oso panda llama la atención en la plaza entre la gente - The panda bear ____ in the town square amongst the people.
Look out when you're reading something or you listen to someone using this phrase, write down those sentences if possible and try to write similar others, hope you feel ready to start using it soon!
¡Hasta la próxima! :)