lst = [['abc', 'def',1,11],['cde', 'fef',2,22],['efg', 'pqr',3,33]]
result = []
for l in lst:
	res = []
	for i, s in enumerate(l):
		if isinstance(s, str):
			if len(res) > 0 and isinstance(res[i-1], str):
				res[i-1] += f" {s}"
			else:
				res.append(s)
		else:
			res.append(s)
	result.append(res)

print(result)