 Hello and welcome. This short video discusses a phonological effect that should prevent us from using particular abbreviated forms in writing. As you know, present-day English tends to use shorthand forms for multi-word phrases, for example this one, where the letter U and the number 2 are combined meaning U2. But sometimes these forms are not in line with connected speech effects. For example this one, what's wrong with it? Well, here is the solution. Surely, when we spell out this form, we want it to mean for you, with the stress on U. This in turn means that the preposition 4 would be unstressed and realized as a weak form for you. The number 4 however has no weak counterpart. Thus, the item 4U is a simple combination like 6x or 25b, but it does not mean for you.