失语

to let slip / loss of speech (e.g. as a result of brain damage) / aphasia

to let slip / loss of speech (e.g. as a result of brain damage); aphasia

to lose / to miss / to fail

dialect / language / speech

to tell to

aphasia or aphemia (loss of language)

mixed aphasia

subcortical aphasia

expressive aphasia

phonetic aphasia

progressive aphasia / gradual loss of speech

primary progressive aphasia (PPA), speech disorder (sometimes related to dementia)