I am hard to speech, its a cause of dehydration?

Tricky: cannot say in your particular case, but generally, if there is a lot of volume/salt depletion, the nerves and brain will not work totally well and this can affect all neurological functions including speech.

Dry mouth: will do it, drink water, but don't sip. Also use Lemmon drops or chew gum

Here are some ...: Talking a long time leads the dryness of oral mucosa, in turn, leading to water drinking to moist the mouth but would not enough to cause systemic dehydration. Hard to speak may reflect the tiredness of mental status, which may result from drug use or some inherent disorders of CNS. So, seek professional evaluation and counseling timely so to define its cause for timely care.

Dr Anyanwu and another doctor agreed