Tight Train Connections Paris to Lauterbrunnen

Yes, I've taken plenty of French and Swiss trains. The French trains are good on time, and the Swiss are fantastic. You can set your watch using the Swiss trains. So if you pulled connections off the SBB site, you should be fine.
When you get to a connecting town, you can check the schedules on the train platform, or, if that's confusing, just ask. Point to a train or the tracks and ask a conductor, "Interlaken?" or whatever train you need. If the connecting train is there they'll point you to it, or tell you the track number. If you don't understand their spoken numbers, just hold up your fingers like you want a number. They start numbering with the thumb, so for "2?" you'd hold up a thumb and forefinger and look quizzical. In France and French Switz., the track number is under "voie" and for German Switz. it's "Gleis". Every conductor should be able to understand basic English.

The only "tricky" part is at Interlaken:
You need to make the connection at the Interlaken “Ost” station, not Interlaken “west”.
The Lauterbrunnen train (usually on the track nearest the station) comes in two sections. One section is marked “Grindelwald” on the cars, the other “Lauterbrunnen” on the cars. The train will separate at Zweilutschinen.

First, what is your schedule, dates, times, train numbers. Do any of your tickets give track numbers?

I've made plenty of connections with less than 10 minutes. In a small station that is plenty of time, but it really helps to know the track numbers. The conductor should know the track number of connecting trains. The word, in German, for track, is Gleis (pr glice). I don't know what it is in French. I'm sure someone will tell you soon. Basel and Interlaken are German speaking, but being Switzerland they will probably know French (or English).

I would worry about 10-minute connections in Switzerland only if burdened by heavy luggage that would slow me down as I went down a flight of steps and back up. In that case I'd try to find out ahead of time--via online station diagrams--whether my transfer stations have elevators. If present, I'd know to head for them if I didn't have just a cross-platform transfer. If I couldn't find the information online, I'd hope to strike up a friendship with an English-speaking local on the train who might know about the elevator situation.

I've never traveled in Switzerland with heavy luggage, so I have no idea whether there are elevators there. On last year's trip to Italy and Germany, I found that some stations had elevators and some did not.

In French, platform is "voie."

This looks like the same question that was posted last week?

You should be able to make these.
1) be at the door, in position to depart, before the train pulls into the station.
2) pack so that each person can handle their own luggage, even if you must go up or down steps. There are usually ramps or elevators around if necessary, but they do add a little time to find them.
3) If feeling pressed for time, make sure you get on the correct train, and worry about getting in the correct car after you board. (Small disclaimer: if the train is going to split, do worry about getting on the correct part of the train)

Are you sure you are really routed through Lyon? I know when you posted this question last week people asked for clarification. I see you still list it on the route. Make sure you double check your route.

The trick at Interlaken Ost is to board the right cars, as the train splits at Zweiluetschinen, and one half goes to Lauterbrunnen and the other half goes to Grindelwald. The individual train cars are marked with their destination, and the experienced station attendants are accustomed to the confused tourists, so will be helpful, if a bit rushed as it is indeed a fast connection.

When traveling to Wengen with a large group, we arrived at Lauterbrunnen to find 3 separate trains on the track for Wengen. The station attendants were shouting in English "Get on any train!" We did as we were told and quickly learned why. Because the track to Wengen has very tight turns, the maximum train length is 3 cars, so instead of sending up a 9-car train, they send up three 3-car trains separated by 50 meters. They've been doing this for a while, so they know what they're doing.

Even if you do miss your connection at Interlaken Ost, there will be another train in 30 minutes you can take. So not to worry.

And we are still confused by your itinerary:

We have a four train connection trip Paris-Lyon-Basel-Interlakken Ost-Lauterbrunnen

I am not finding any direct trains between Lyon and Basel. Could you post your itinerary as it is written on your ticket. If I was in Lyon and going to Lauterbrunnen, I certainly would not go via Basel.

At Interlaken Ost station there will be plenty of train personnel out on the platforms directing the tourists to the correct trains...and they all peak very good English (and German and French and Italian, etc).

Your limited French won't matter in Interlaken Ost. ;-) There it will be German with very little English.

I've been going to the Berner Oberland at least once or twice a year for a decade. That has not been my experience.

One thing that the Berner Oberland gets is tourists. It has done for well over a century. It gets tourists from all over the world and very few of the Chinese, Japanese, Korean, Mexican, Nigerian, Russian and another hundred country visitors speak German, much less Swiss German. The people in the tourist industry - trains, hotels, bike rentals, restaurants, etc. - know this and in order to keep them happy and coming back they have learned tourist English. When a Chinese tourist sits next to a visitor from Romania and they both need tickets - they all speak English (at whatever level) to one another.

Keep your English fairly simple (but not childlike) and free of slang and you will be absolutely fine, both with staff and fellow travelers.

Chris' contribution to your earlier post is key: From Basel, you need not catch the specific Swiss departures listed; any train on that prescribed route is fine. And are you departing from Paris' Gare de Lyon? It's perhaps not the best name for a train station in Paris, but it serves southbound to Lyon and beyond, plus the direct TGV to Basel.

Thank you all!
Yes my post was more confusing than should be
Your are right not routed through Lyon ( Leaving from Paris-Gare De Lyon . Days later we go thru Lyon on our Geneva to Nimes leg!)
And yes only 2 stops and 3 trains.
Looks like all think 'doable'. And sure seems like SBB would know.
The Paris to Basel TGV is leaving from Platform 10 (and looks like arrives at Platform 9 so does this mean these are two rail lines just next to each other?)
Same question re arriving at Inerlaken Ost on Platform 7 and leaving from Platform 2A (? just five over? or not that simple?)

So thanks for the reassuring clarifications...

No Heavy luggage so all should be mobile and good to go!

"Same question re arriving at Inerlaken Ost on Platform 7 and leaving from Platform 2A (? just five over? or not that simple?)"

That sounds about right. I seem to recall only about 8 tracks total at Interlaken Ost. It's not a huge town.

I've learned to pay particular attention to train platforms when I see letters included. Platform 2A may be different from Platform 2. Or perhaps the two ends of that platform have been assigned different letters?? I once got on the wrong train in Luxembourg because I ignored the fact that my train was departing from Platform 1x and I was standing on Platform 1.

There may not be anything strange going on at Interlaken Ost, but do pay attention to the platform markings.