I am a staff at the Ministry of Religious Affairs.
Although you will occasionally find an example of staff as a countable noun, it is extremely rare.
Used as an uncountable noun, staff refers to people who work for a particular organisation:
- Staff at the Ministry of Religious Affairs receive a competitive salary.
Used as a countable noun, a staff is a kind of stick with certain features and functions:
- often very long – longer than its user is tall
- usually made of wood
- usually quite ornate, possibly hand-crafted
- used by someone with special powers, for example a wizard
- often used in specialised fighting, like kung fu
- otherwise used to assist in walking (elderly people, etc)
- He used his staff to scare away evil spirits and then used it to turn my horse into a brand new Ferrari. I noticed the staff also helped him to walk!
In the context of your writing one of these meanings, staff countable / staff uncountable, will probably be more obvious than the other. However, if you want a high score in IELTS for vocabulary, I suggest you choose the most appropriate meaning!
If you really must use a countable noun, you can do this:
- I am a member of staff at the Ministry of Religious Affairs.
Moreover, a failure can be caused by a lack of practical experiences.
It’s annoying, I know, but while some nouns are countable and others are uncountable, yet others can be either countable or uncountable, and here are two examples in the same sentence: failure and experience.
Generally speaking, if a noun can be either countable or uncountable, and if you’re speaking generally, use the uncountable form. On the other hand if you’re talking about specific things then use the countable form – for example you may be talking about the time you failed an exam and saying what a terrible experience that was.
In the original example, I think we’re talking generally, right?
- Moreover, failure can be caused by a lack of practical experience.
Meanwhile, using the countable versions of these words:
- His brothers were all successful, but he was a failure. Receiving his exam results was an experience he would like to forget!
Children these days spend a lot of time using interactive media which increases their exposure to aggressive contents.
It’s difficult to imagine contents behaving aggressively:
Take a look at some examples of sentences using content (uncountable) and contents (plural countable). Remember that when you’re talking about something that can be countable or uncountable, and if you are writing in general terms about that thing, then you should use the uncountable form.
- Children these days spend a lot of time using interactive media which increases their exposure to aggressive content.
The government need to make more of an effort to fight crimes.
Crime can be countable or uncountable, and as with other nouns that behave like this, the uncountable form has a more general meaning and the countable more specific.
Another way to look at this is to notice that fight and crime (without ‘s’) collocate strongly:
- The government need to make more of an effort to fight crime.
Try googling fight crime and fight crimes. Which is more common? What are the differences in meaning?