usage of expression "to lose focus of"

[hereinchina]

Hello,
According to the Macmillan online dictionary, the meaning of the word "focus" is the following: "to concentrate on something and pay particular attention to it." Can you use the expression "lose focus of (something)" to mean that you stopped paying attention to something, stopped concentrating on it? In other words, do the following sentences make sense and are they grammatically correct?
1. When my colleague distracted me, I lost focus of the email I was writing.
2. When I heard my neighbor's screams, I lost focus of what I was doing.
3. When my classmate kept asking me questions, I lost focus of what my teacher was saying.

[fluffyhamster]

This is one of those items that isn't in dictionaries (doesn't that ever give you or your students any pause for thought LOL), but that people would probably pass over silently enough - until you asked them to comment regarding the acceptability of it, that is!

Possible alternatives (other than 'could no longer concentrate on' etc) could be: 'lose track of sthg' (seems suited to vague activities phrased 'what X be v-ing', but with more definite objects would suggest you actually lost/couldn't find them: I lost track of the email I was writing), and 'lose the thread of sthg' (which would appear suited to all your examples).

Another reason for mentioning 'lose track of sthg' and 'lose the thread of sthg' is that there is an obvious difference between them, namely the definite article 'the'...which could be one reason for the possible aversion to/relative unattestedness of 'lose focus of'; that is, I think one can 'lose focus' (and in this more or less set phrase lose only that, just the lone object 'focus'), or 'focus on sthg', or talk about 'the focus/aim of sthg is blah blah blah', and finally, say that you 'lost the focus of the email you were writing' (so that it became unfocussed, and badly-written as a result), but 'lose focus of' perhaps sounds like it is missing the article or something (compare *lose thread of; *focus of this post is...).

So I guess that without the 'the' breaking things up into a more explicit verb + noun, there could be a tension of sorts between the verbal process of you "losing focus" (not that the 'focus' in 'lose focus' is a second verb in series or anything - it's still a noun here!), versus the nominal i.e. noun "focus of the thing you were doing". (I find colons help in these sorts of cases - compare ?I lost: focus: of the email I was writing with I lost: the focus of the email I was writing).

But like I say, I doubt if most people would object to it unless you specifically asked them about it.

[hereinchina]

Hello,
Once again, thank you for taking the time to answer my question.
Best wishes,