Interested in Language
Hello there... Could you shed some light on this?
My job is to protect you.
All they do is talk.
Please, dear teachers and friends, why do I think there should be a 'to' before 'talk'?
Protecting you is my job
To protect you is my job.
Talk is all they do.
Are the sentences above right?
So, I could say "my job is protect you" fearlessly and everyone will take it?
Well... I have to double my studies... I mean... listen to the radios more often.
No. You can't say "my job is protect you". Nor can I explain why. But "all she [ever] does is verb" is fine.
These omissions are a strange thing. One slip and you're out. This is where the writers of automated morphological/syntactic parsers go grey. Probably best to take it on a case-by-case basis.
PS I need hardly point out I'm talking about N. American English.
All they do is sing.
All they do is to sing.
Learning English | BBC World Service
Swan PEU 130.5
All (that they do) is talk (=noun). -- SVC
All that they do is to talk. -- SVC -- infinitive clauses may be realized as noun phrases