Can I use "when" here?

Question

"In almost all of the studies to date, when alcohol was utilized in engine, it showed a trend of decreasing."

In above sentences: Can I use "when" here? after the "In almost all of the studies to date" ?

Answer 1

Technically you should use 'where' instead of 'when', because you are talking about 'where' the alcohol is utilized, i.e., 'in an engine'. However, it is not uncommon to hear native English speakers say 'when' in phrases such as this.

Technically 'when' is better suited to clauses discussing periods of time, or points in time, when something occurred, rather than where it occurred. For example,:

Studies show that when alcohol-enriched fuels were first released the take-up rate among motorist was quite minimal; with current soaring fuel costs it is becoming quite popular.

(Some sentences in this answer have been made-up to demonstrate the use of the English language. I know nothing about using alcohol in fuel, so don't regard anything I say about fuel as being true.)

Your sentence has a couple of minor errors you may want to address. You can do this by pressing the 'edit' button immediately below your comment. If you make any changes, you will then need to click on the button that says 'Save Edits', which is usually lower down on your page. If you have any problems doing this, Click on the 'add a comment' button and ask for help. Either I or someone else will respond.

1/ Your sentence came to an abrupt end. You can't mention a trend increasing, or decreasing, without mentioning what it was that increased or decreased. e.g.

...engine, fuel consumption tended to increase which cancelled out the benefits of lower cost fuel.

...engine, it showed a trend of decreasing toxic fuel emissions, which eventually plateaued out after the engine had been driven for 500 miles.

2. '...utilized in engine,...' You cannot say this in this way. 'engine' should have 'an' or 'the' in front of it. 'engines' can have either'the' or nothing in front of it. You should think about changing it to one of the following:

'...utilized in an engine,...'

'...utilized in engines,...'

or, if you have mentioned 'an engine' previously in your article '...utilized in the engine,...',

3. You may also want to think about mentioning what sort of engine you are referring to, e.g. 'a petrol-powered engine' or 'a gas-powered engine' in the USA. Alcohol is not usually added to diesel or steam engines. If this sentence is part of a longer article, and you have already mentioned the type of engine, you can say 'engine' as you have without saying what type of engine it is.