Lack of vocab?

I’m on Ch2 lesson 11 and although i am enjoying the course have thought for some time that there is not much vocab in it.
I listened to Ch2/11 today for the first time and although you are introduced to new items like ‘we were going to do’ ‘on i’n mynd i wneud…’ the rest of the words used in the practice sentence are not new, and uses old sentences used in previous lesson like for example ’ watch tv on sunday afternoon’.
The last new word introduced was ‘cyflawni’ ‘to achieve’ a few lessons back.

Is this part of the learning technique? I’m trying to increase my vocab slowly by reading books for Welsh learners but think more vocab in the lessons to go along with the sentence structures we learn would be beneficial.

Building up vocab has been discussed quite often before. If you key in ‘vocab’ to the search box top right, this will give a number of threads on the topic. A good one is:

and I’m sure @delawarejones won’t mind me reproducing his excellent set of resources:

Intro Word/phrases and pronunciation -
Intermediate Words/phrases and pronunciation -
Lots of words here -
BBC has lists for both North and South -
SSiW Gair y Diwrnod - Gair y Diwrnod - Word of the Day

(I find the American one particularly good).

Others have also suggested Duolingo and Memrise as good sources.

I think the main focus of SSIW is to get you talking Welsh, which it does like no other learning method, but it can’t be expected to do everything. When it comes to wider vocab, people’s needs are different according to their interests, so are encouraged to use these various sources. As for repeating words in the practice sentences, well I guess there has to be a degree of familiarity - with new structures being introduced all the time, if all the vocab was new as well, some folks might be complaining about sensory overload!