Offer them a paper with expressions that might help them to speak.
Such as,
in my opinion
I agree / disagree with
etc.
Encourage them to organise a good notebook. They can build families of words related in meaning.
You give them a word, e.g. 'feelings' and they have to look for words that can be grouped under this heading.
This is a good opportunity to introduce the using of diagrams (e.g. bubble network)
feelings
bad: sad, angry, desperate, sorrowful ...
good: happy, glad, cheerful, content, joyful, grateful ...
This might do the trick. They will learn more words and thus become more confident with speaking English.
Encourage them to use these new words.
Regards,
Snowcake