I have never owned a garden before in my life (and as such, am only now learning that lawns need maintenance), but: I bought a house about 18 months ago that has a lawn roughly about a third of an acre (1.3km sq), and almost all of it is lawn grass:
Last summer here (in the UK) was absolutely brutal - it didn't rain at all for around 2 months, and temperatures were regularly in the 30s (Celsius), reaching a record-breaking 40c. In that time, pretty much the entire lawn died. I tried watering & fertilising it at the time, but practically the whole lot went yellow in spite of this.
It slowly came back, and by winter most of it was green again; however it is now absolutely strewn with moss and some kind of weedy leaves:
A couple of weeks ago I scarified it with a towed scarifier for my ride-on, going both vertically and diagonally, then raked it all up by hand, but there was still plenty left. So last weekend I doused the lawn in iron sulphate using a backpack sprayer, about 900g to 20l of water. The patches of moss then went black (but the weeds were untouched), and so I scarified again today, which dragged up a lot more moss. I then attempted to go over it manually with a rake again to collect it all up, but even still there are big patches where the moss is inextricably entwined with blades of grass. And nothing seems to be touching these weeds, which are very flat, lower than the level of the grass.
I was going to reseed after today, but at this point I'm not sure. Should I continue to rake/scarify to attempt to get every inch of moss? Or is what I've done so far good enough to get it restarted? And should I just use a standard weedkiller on the patches of leaves (some of the patches are VERY large), or try to pull them by hand?