The first word that came to my mind was "articulate".

articulate verb: 3rd person present: articulates; past tense: articulated; past participle: articulated; gerund or present participle: articulating

1. express (an idea or feeling) fluently and coherently. "they were unable to articulate their emotions"

synonyms: express, voice, vocalize, put in words, communicate, state see, Google.com articulate

Or, of course, the circumstance OP describes (its lack), "inarticulate".

inarticulate adjective:

1. unable to speak distinctly or express oneself clearly. "he was inarticulate with abashment and regret"

synonyms: tongue-tied, lost for words, unable to express oneself "an inarticulate young man" see, Google.com inarticulate

The first word that came to my mind was "articulate".

articulate verb: 3rd person present: articulates; past tense: articulated; past participle: articulated; gerund or present participle: articulating

1. express (an idea or feeling) fluently and coherently. "they were unable to articulate their emotions"

synonyms: express, voice, vocalize, put in words, communicate, state.
see, Google.com articulate

Or, of course, the circumstance OP describes (its lack), "inarticulate".

inarticulate adjective:

1. unable to speak distinctly or express oneself clearly. "he was inarticulate with abashment and regret"

synonyms: tongue-tied, lost for words, unable to express oneself. "an inarticulate young man" see, Google.com inarticulate

The first word that came to my mind was "articulate".

articulate verb: 3rd person present: articulates; past tense: articulated; past participle: articulated; gerund or present participle: articulating

1. express (an idea or feeling) fluently and coherently. "they were unable to articulate their emotions"

synonyms: express, voice, vocalize, put in words, communicate, state see, Google.com articulate

The first word that came to my mind was "articulate".

articulate verb: 3rd person present: articulates; past tense: articulated; past participle: articulated; gerund or present participle: articulating

1. express (an idea or feeling) fluently and coherently. "they were unable to articulate their emotions"

synonyms: express, voice, vocalize, put in words, communicate, state see, Google.com articulate

Or, of course, the circumstance OP describes (its lack), "inarticulate".

inarticulate adjective:

1. unable to speak distinctly or express oneself clearly. "he was inarticulate with abashment and regret"

synonyms: tongue-tied, lost for words, unable to express oneself "an inarticulate young man" see, Google.com inarticulate