Q:

What is the difference between 言いだし and 言いだす?

I found a sentence earlier containing the word 言いだしづら but I parsed it to 2 words and I found I did not know 言いだし so I looked it up and found 言いだす (which I know the meaning of), but I also found another site saying 言いだし is the same thing basically, but I don't know why there is a し. Is this a different word or a conjugation I forgot?

A:

言いだし is the continuative form (連用形) of 言いだす ([言]{い}い[出]{だ}す).

Examples:
  dictionary form - continuative form
  [言]{い}う - 言い
  [出]{だ}す - 出し
  言いだす - 言いだし
  する - し
  わかる - わかり

「[Continuative form of a verb] + づらい」 means "hard/difficult to [Verb]".
づらい comes from an i-adjective つらい ([辛]{つら}い), "painful, difficult, tough, hard". The つ gets voiced into づ due to [連濁]{れんだく}.

Examples:
  言う + つらい → 言いづらい "hard to say"
  言いだす + つらい → 言いだしづらい "hard to start talking / hard to speak out"
  わかる + つらい → わかりづらい "hard to understand"
  外出する + つらい → 外出しづらい "hard to go out" 

