He tried to speak but did not know what to say.

He seemed to be trying to speak, but could not.

He tried to speak but she couldn't make out the words.

She tried to speak but couldn't seem to get anything out.

Several of the men did try to speak to him, but most came only to look.

She tried to speak, but not a word would come.

He tried to speak, but I could not hear him.

He tried to speak a couple of times and couldn't.

We have been trying to speak with them without success.

She tried to speak, but nothing would come to her.