hey UG members, I got a problem

I play acoustic and the main things I play are songs with chords and singing. but my problem is that I can strum and sing at the same time but when it comes to strumming in certain patterns like ( down down up up down up ), I can't sing whatsoever or get a word out of my mouth. I always end messing up.

can someone recommend a technique so I can conquer this problem?

thanks a lot.
learn to do the pattern or the song with having to think about it once you have the guitar part down cold doing both parts shoud get much easier
Make your mouth and your guitar one with each other.
seriously though, its about keeping sync with each other. Use your strumming patterns as a guide on how to sing.
do you sing on key with your guitar playing?
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Get the rhythm of the guitar down perfect and when I say perfect, I mean so you can play it without even thinking about the rhythm part. Once you do that, it should be easier to sing the song with the guitar.

Squier Tele Custom ii (p90 version)

Orange Crush 10

Fender CD140S
For me I just practice playing the guitar parts until I have them down comfortably where I can play without thinking. I'll then record the guitar part on my camera or recorder so I can come up with a vocal melody. Once I have the melody down I put the two together. If you're learning songs where you already know both parts, it's about perfecting them seperately and bringing them together. With consistent practice you'll be able to get it. It just takes time and persistence.
Just imagine being part of a metal power trio where you have the guitarist playing riffs, licks and solos all while singing. It's like patting your head and rubbing your stomach. I'm useless at it too.
I have a similar problem, where I can sing and play as long as there is strumming, but it goes to shit if it's an intricate riff being played. Silent Lucidity is a good example. I can't sing and play it the correct way, but if I strum the chord progression I can pull it off.

But there are other songs that I've played for so many years now that I can sing and play (as long as it's somewhat simple). An example of this is 1979 by the Pumpkins.

I think some peoples brains can allocate attention to multiple tasks, but others have to work really, really hard at it, and even then it's not 100% either way. I developed a newfound respect for people like James Hetfield who are capable of playing and singing equally well at the same time.