“大胆说英语怎么讲

“Don't be afraid to speak English.” 比较正式
“just speak out, don't be shy!” 比较随意

Speak out - don't be afraid!

speak out English with courage

dare(s) to speak English

speaking English fearlessly
just speaking out
don't be afraid!
come on!

"Don't be afraid to speak English." - 是正确的， ok 的.
"Feel free to speak English." - 是正确的. 它是更好.